Pair Of Linear Equations In 2 Variables | Complete NCERT BACK EXERCISE in 1 Video | Class 10th Board

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✨ Topics covered ✨

00:00 - Introduction
02:23 - Exercise - 3.1
01:10:10 - Exercise - 3.2
02:13:30 - Exercise - 3.3
02:58:16 - Thank You !

#Class10th #Udaan #pairoflinearequationintwovariables #pairoflinearequationintwovariablesrevision #mathssolutions #class10maths

Good luck with your studies! 🎓✨

[Classth-UDAAN]

Padhai ko aur easy karne ke liye ye telegram group join karo 🤩

[Arnav_]

1:29:27-
(vi) (3x/2) - (5y/3) = - 2 ...(1)

x/3 + y/2 = 13/6 ...(2)

Multiply both the equations (1) and (2) by 6, to remove the denominatores and making it easier for calculation.

[3x/2 - 5y/3 = - 2] × 6

9x - 10y = - 12 ...(3)

[x/3 + y/2 = 13/6] × 6

2x + 3y = 13 ...(4)

By solving equation (3)

9x - 10y = - 12

10y = 9x + 12

y = (9x + 12) / 10 ...(5)

Substituting y = (9x + 12) / 10 in equation (4), we get

2x + 3 [(9x + 12) / 10] = 13

(20x + 27x + 36) / 10 = 13

47x = 130 - 36

x = 94/47 = 2

Substituting x = 2 in equation (5), we get

y = (9 × 2 + 12) / 10

y = 30/10

y = 3

Thus, x = 2, y = 3

1:48:50 -
Let the cost of 1 bat = ₹ x

And the cost of 1 ball = ₹ y

7x + 6y = 3800 ....(1)

3x + 5y = 1750 ....(2)

By solving equation (1),

7x + 6y = 3800

6y = 3800 - 7x

y = (3800 - 7x) / 6 ....(3)

Substituting y = (3800 - 7x) / 6 in equation (2), we get

3x + 5 [(3800 - 7x) / 6] = 1750

(18x + 19000 - 35x) / 6 = 1750

-17x + 19000 = 1750 × 6

17x = 19000 - 10500

x = 8500/17

x = 500

Substituting x = 500 in equation (3), we get

y = (3800 - 7 × 500) / 6

y = 300/6

y = 50

Cost of 1 bat is ₹ 500

Cost of 1 ball is ₹ 50

2:04:20-

) Let the numerator = x

And denominator = y

Then the fraction is x / y

When 2 is added to both numerator and denominator,

(x + 2) / (y + 2) = 9/11

11(x + 2) = 9( y + 2)

11x + 22 = 9y + 18

11x - 9y + 22 - 18 = 0

11x - 9y + 4 = 0 ...(1)

When 3 is added to both numerator and denominator

(x + 3) / (y + 3) = 5/6

6(x + 3) = 5( y + 3)

6x + 18 = 5y + 15

6x - 5y + 18 - 15 = 0

6x - 5y + 3 = 0 ....(2)

5y = 6x + 3

y = (6x + 3) / 5 ....(3)

Substituting y = (6x + 3) / 5 in equation (1)

11x - 9 [(6x + 3) / 5] + 4 = 0

[55x - 9(6x + 3) + 20] / 5 = 0

55x - 54x - 27 + 20 = 0

x - 7 = 0

x = 7

Substituting x = 7 in equation (3) we get,

y = (6 × 7 + 3) / 5

y = (42 + 3) / 5

y = 45/5

y = 9

Thus, the fraction is 7/9.

Substitution method:

2:20:30-
(ii) 3x + 4y = 10 ....(1)


2x - 2y = 2 ....(2)

By solving equation (1)

3x + 4y = 10

4y = 10 - 3x

y = (10 - 3x) / 4 ....(3)

Substituting y = (10 - 3x) / 4 in equation (2)

2x - 2[(10 - 3x) / 4] = 2

(4x -10 + 3x) / 2 = 2

7x - 10 = 4

7x = 4 + 10

x = 14/7

x = 2

Substituting x = 2 in equation (3)

y = (10 - 3 × 2) / 4

y = (10 - 6) / 4

y = 4/4

y = 1

Thus, x = 2 and y = 1
(iii) Substitution method:

3x - 5y - 4 = 0 ....(1)

9x = 2y + 7 ....(2)

By solving equation (1)

3x - 5y - 4 = 0

5y = 3x - 4

y = (3x - 4) / 5 ....(3)

Substituting y = (3x - 4) / 5 in equation (2)

9x = 2[(3x - 4) / 5] + 7

9x = (6x - 8 + 35) / 5

45x = 6x + 27

45x - 6x = 27

39x = 27

x = 27/39

x = 9/13 [By simplifying and reducing the fraction]

Substitute x = 9/13 in equation (3)

y = [3(9/13) - 4]/5

y = (27 - 52)/13 × 1/5

y = - 25/13 × 1/5

y = - 5/13

Thus, y = - 5/13 and x = 9/13
(iv)
Substitution method:

x/2 + 2y/3 = - 1 ...(1)

x - y/3 = 3 ...(2)

By solving equation (2)

x - y/3 = 3

x = y/3 + 3

x = (y + 9) / 3 ....(3)

Substituting x = (y + 9) / 3 in equation (1)

[(y + 9)/3] / 2 + 2y/3 = - 1

(y + 9 + 4y)/6 = - 1

5y + 9 = - 6

5y = - 6 - 9

y = - 15/5

y = -3

Substituting y = -3 in equation (3)

x = (- 3 + 9) / 3

x = 6/3

x = 2

Thus, x = 2 and y = -3

2:32:46-

Let the numerator = x

And the denominator = y

Then the fraction = x/y

When 1 is added to the numerator and 1 is subtracted from the denominator, the fraction reduces to 1 as shown below.

(x + 1)/(y - 1) = 1

x + 1 = y - 1

x - y + 1 + 1 = 0

x - y + 2 = 0 ...(1)

When 1 is added to the denominator, the fraction becomes 1/2 as shown below.

x/(y + 1) = 1/2

2x = y + 1

2x - y - 1 = 0 ...(2)

By subtracting equation (2) from equation (1)

(x - y + 2) - (2x - y - 1) = 0

x - y + 2 - 2x + y + 1 = 0

- x + 3 = 0

x = 3

Substitute x = 3 in equation (1)

3 - y + 2 = 0

y = 5

Equations are x - y + 2 = 0 and 2x - y -1 = 0 where the numerator of the fraction is x, and denominator is y.

The fraction is 3/5.

2:36:24-
Let the present age of Nuri = x years

And the present age of Sonu = y years

5 years ago,

Nuri’s age = (x - 5) years

Sonu’s age = (y - 5) years

x - 5 = 3(y - 5)

x - 5 = 3y - 15

x - 3y - 5 + 15 = 0

x - 3y + 10 = 0 ...(1)

10 years later,

Nuri’s age = (x + 10) years

Sonu’s age = (y + 10) years

x + 10 = 2(y + 10)

x + 10 = 2y + 20

x - 2y + 10 - 20 = 0

x - 2y - 10 = 0 ...(2)

By subtracting equation (2) from equation (1)

(x - 3y +10) - ( x - 2y -10) = 0

x - 3y +10 - x + 2y +10 = 0

- y + 20 = 0

y = 20

Now, substitute y = 20 in equation (1)

x - 3 × 20 + 10 = 0

x - 60 + 10 = 0

x - 50 = 0

x = 50

Linear equations are x - 3y +10 = 0 and x - 2 y -10 = 0 where the present age of Nuri is x and Sonu is y

The age of Sonu is 20 years and age of Nuri is 50 years.

2:51:47-
Let number of notes of ₹ 50 = x

Number of notes of ₹ 100 = y

Meena got 25 notes in all;

x + y = 25 ...(1)

Meena withdrew ₹ 2000;

50x +100y = 2000

50(x + 2y) = 2000

x + 2y = 2000/50

x + 2y = 40 ...(2)

By subtracting equation (1) from equation (2)

(x + 2y) - (x + y) = 40 - 25

x + 2y - x - y = 15

y = 15

Substituting, y = 15 in equation (1)

x + 15 = 25

x =10

Equations are x + y = 25 and x + 2y = 40 where number of ₹ 50 and ₹ 100 notes are x and y respectively.

The number of ₹ 50 notes is 10 and the number of ₹ 100 notes is 15.

2:57:59-
Let the fixed charge = x

Charge per extra day = y

Saritha paid ₹ 27 for a book kept for 7 days;

We know that the lending library has a fixed charge for the first three days and an additional charge for each day thereafter.

Therefore,

x + (7 - 3) y = 27

x + 4y = 27 ...(1)

Susy paid ₹ 21 for a book kept for 5 days;

x + (5 - 3) y = 21

x + 2y = 21 ...(2)

By subtracting equation (2) from equation (1)

(x + 4 y) - (x + 2 y) = 27 - 21

x + 4y - x - 2y = 6

2y = 6

y = 6/2

y = 3

Substituting y = 3 in equation (1)

x + 4 × 3 = 27

x + 12 = 27

x = 27 - 12

x = 15

Equations are x + 2y = 21 and x + 4y = 27 where fixed charge is ₹ x and charge for each extra day is ₹ y.

The fixed charge is ₹ 15 and the charge for each extra day is ₹ 3.

[Girl]

1:48:51 ATTENTION ⚠️ Equation is wrong ... 1:48:51 So that's why when I' try more times to solve but my answer comes wrong so the right equation is :=
7x+6y=3800
3x+5y=1750
In video this "1750" change in "1780" So write the right equation...👍🏻✨*

[Lucky__thakurst]

Jisne bhi like nhi kiya vo 💯 percent fail hoga

[SandipDukare-fdnf]

Legend are watching one day before exam like here nahi to fail❤❤❤

[certifieddd_yapperrr]

Guys I really want you all to study from Ritik sir in Class 10th coz' before watching his lectures I always get less marks in Maths but after watching his lectures I feel very confident and I starting loving Maths and when I see paper I feel like I have done this question he's awesome ❤❤ Thankuuu ❤❤

[Lakshit-pk]

1:10:00 If anyone getting confused take it simple if you take any other values of x and y it's completely Because in question is has mentioned that you have to take x axis as the base of triangle... 😊❤❤❤hope this help you.. Even i was confused first😅

[billionstalkinfiniteenergy]

😂I will not tell u to like my comment to score 95%+ or 100marks in boards 😂I just want to say go and work hard don't waste time in watching comments in between lectures 😂😂😂😂😂😂😂😂😂😂jao padho exam he kl

[crickety]

Exam is near "
"Nothing is clear"
"No need to fear"
Because our favorite PWs😍 sir is here ❤❤❤

[be_confidentandhappy]

Thanks to whole PW team for working so hard for us ❤️

[Datafacts]

Well as an Average student, I wish I could score above 80%.

[Ace_wss]

After an amazing 😊 lecture we should thank them and they are saying thanku

[CRICKETEXPLAINERYT]

2:54:51 kaash school me aisa concept clear krte to vahi teacher se same cheez coaching me na padhne padta uske bad bhi clear YouTube me hora h

[fake]

40:30
Actually vaha par minus sign nahi de rakha so vo consistent hogaa! (5x-3y=11) not ( -5....) So vaha par -1/2 ki jagah 1/-2..aata
Correct me if I'm wrong

[AnanndShri]

I hope allow of you get better marks in boards exam❤

[rakshitrajput]

Maths is feel so simple when I see your lecture

[aamirahmed]

28:19 Sir is ma coincident system nahi aata consistent aata BTW love u Babua❤❤❤❤ 28:19

[JATIN-KASHYAP]

1:11:45 Anyone notice what did he say 😅😅 💀💀🗿🗿

[Theclown]

2:46:36
Yeh dekh Ke Jana haste haste jawo gay
BTW I am not insulting sir just wanted to make others laugh.

[MKBAGHEL-bk]

2:51:39 no.of notes of Rs.50 is 10
And no.of notes of Rs.100 is 15

Thankyou so much sir 😊😊😊😊