3x^2(-6x^3-7+8x) simplified

-18x^5 +24x³-21x²

Sooo all you gotta do is just distribute the 3x² through the parenthesis. Dont forget that when you multiply exponents, you're really just adding them. Also don't forget to put the simplified answer into standard form (which is just putting the exponents from greatest to least).

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk