Maths Olympiad | A tricky Algebra Maths Olympiad Questions | 8^x +2^x =130.

Hello everyone , ,Welcome to Rashel's classroom. In this video i solve maths olympiad question. Its a tricky maths problems. Algebra problem .
#maths #math #mathematics

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[ChinalurumUkairo]

Instead, you could just notice that u^3 + u - 130 is the same as u^3 - 125 + u - 5 so then you can do some factorisation to get to (u-5)(u^2 +5u+25) + (u-5), which is (u-5)(u^2 +5u+26). Then, by noticing that u-5=0, you can get u=5. Simple.

[aiming...-esqj]

Its very simple guys
8^x=2^3x
Therefore the eqn simply becomes y^3+y-130=0 by hit and trial y=5 then you what to do next 😊

[TENTHWALA]

8^x + 2^x = 130
(2^3)^x + 2^x = 130
2^3x + 2^x = 2^7 +2^1
3x + x = 7+1
4x = 8
X= 8÷4
X =2 answer
This is right solution

[DS-tcww]

I don't like this "trial and error" method. It's guessing, not mathmatical logic.

[larry]

I went about this in a completely different way.
(8^x-64)+(2^x -66)=0
(2^3)^x-(4^3)+(2^x-66)=0
(2^x)^3-(4^3)+(2^x-66)=0
let 2^x=P
(P^3-4^3)+(P-66)=0
(P-4)(P^2+4P+16+P-66)=0
(P-4)(P^2+5P-50)=0
factors are P1=4
P2=5
P3=-10
-10 is rejected as it is negative
4=2^x is rejected because it does not solve the original equation
5=2^x
xlog2=log5
x=log5/log2 or x=log(base2)5 only valid solution.

[surinetso]

8^x+2^x=130
2^3x+2^x=130
4x=130
X=130/4
X=32.5

[georgesunaryo]

Simply factoring :
2^x(2^3+1)=130
2^x.9=130
2^x=130/9
Log2^x=log130/9
X=log130/9:2
X=log 65/9