SAT Math Hard Problem with Exponents and Difference of Squares

#shorts

This question is hard just because there are many things to remember about it. At least it is a good review.

[gezza]

Another solution is to rewrite as x^2a-2b, meaning that 2(a-b)=16

[davidseed]

Thank you a clear exposition not only of what you are doing bur also. What to remember and what not to do. Ie how to keep on the right path. Oh by the way, when i was young we learnt to chant…
“The difference of two squares is equal to the product of the sum and the difference”

[itsaruvbedi]

That was pretty easy.. even for a 7-8th grader as it implies exponential concepts

[bilifoq]

This one is pretty tricky when you come across it first time but when you recall the (a-b)(a+b) formula everything becomes straightforward.

[anjalidwivedi]

a-b = 8
Saying this question is hard is a joke to SAT exams.
BTW great video as always sir.

[marcoantoniomacedo]

I solved it easily just with a system:
a + b = 2
a - b = c

then my plan was just to replace 'C' with each of the possible answers, the solution was unequivocally gonna come.
So, I started:
a + b = 2
a - b = 8 [wich was the first possible answer]

solved it quickly and got A = 5 and B = -3. And this meant 5 - (-3) = 8, wich was correct.
Therefore letter A.

[mathwithdoge]

I’m a 5th grader and I genuinely thought this was easy.

[Titan_Lord]

I did these type of questions in 7th grade. I am very surprised that they ask such easy questions in SAT.

[abbashusain]

Meanwhile me being a 10th Grader and able to solve a SAT problem directly in my mind

*stonks*

[cxllmegeo]

I’m confused why u can’t just square root both sides when u have. a^2 - b^2 = 16.

[imnoob]

My solution is:

Square root the whole equation and we will come down with this whole new equation

x^a
= 8
x^b

x^a-b =x^8

So a-b is 8

[Collinp-edfi]

Where can i find questions like these to practice on my own?

[chicjaf]

Why is the information x>1 included? I think this equation also works without this assumption. Is it just there to distract people?

[abhigyakumar]

In which class you guys give this exam in NA?

[NatoSkato]

When do yous learn difference of squares in the usa?

[krishsundareshkannan]

@Mathodman Can you say why the title of this video has a word "Hard Problem". This question can be solved easily by a 6th grader.

[pmxi]

if this is hard sat, then it is going to be a piece of cake

[ozi]

Im a 9th grader I solved it in my mind

[RajThakkar]

We literally learn this concept in 8th grade

[devaorios]

HOW IS THIS HARD? you SAT bois have it so easy wtf