Question

PLSSSS HELPPP 18 POINTS MATHHH PLSSS HELPPP

Answer 1

Answer:

$\sf \bf 81x^8$

Step-by-step explanation:

Exponent rule:

  In exponent multiplication, if bases are same, add the exponents.

$\sf \bf a^m*a^n = a^{m+n}$

$\sf (-9x^5)(-9x^3) = (-9)*(-9) * x^{5+3}$

                      $\sf = 81x^8$

Answer 2

Answer:

$81x^{8}$

Step-by-step explanation:

I gotchu again, papiii!! :D

This is an easy one too! Theres a couple rules you should be familair with:

A positive multiplied by a positive is a positive.
A positive multiplied by a negative is a negative.
A negative multiplied by a negative is a positive.

Furthermore, when you have a problem in this form, you MULTIPLY the coefficients and ADD the exponents. So, -9 * -9 = POSITIVE 81, and $x^{5+3}=x^8$. Therefore, the answer is $81x^{8}$