Confussing Exponent

by **ErikaG895** Mon Aug 11, 2014 1:06 pm

Source: Manhattan GMAT CAT Math Quant Section

(3^5x + 3^5x + 3^5x)(4^5x + 4^5x + 4^5x + 4^5x) =
3^5x(1 + 1 + 1) × 4^5x(1 + 1 + 1 + 1) =
3(3^5x) × 4(4^5x) =
3^5x+1 × 4^5x+1 =
(3 × 4)^5x+1 =
12^5x+1

I understand everything in this problem except for the bolded portion. Where did x+1 come from?

Thanks!!

by **tim** Wed Aug 13, 2014 4:22 am

3(3^5x) is really 3^(1) * 3^(5x). Using your rules of exponents, we add the exponents to get 3^(5x+1). Same for the powers of 4.

Confussing Exponent

Confussing Exponent

Re: Confussing Exponent