math
posted by kim on .
how would you factor (5(x+2)^4)+(3x(x+2)^3)(2x(x+2)^2).
I have so far gotten it down to 2(3x^4+25x^3+74x^2+92x+40) but i'm not sure that i am doing this right.

you went the wrong way, you expanded.
notice the common factor of (x+2)^2
so your expression is
(x+2)^2[5(x+2)^2 + 3x(x+2)  2x]
now expand the square bracket, since I don't see any more common factors
= (x+2)^2[5x^2 + 20x + 20 + 3x^2 + 6x  2x]
=(x+2)^2[8x^2 + 24x + 20]
= 4(x+2)^2(2x^2 + 6x + 5) 
I'm building a new fence around my yard. The length is 20 ft. The width is 18 ft long. How much will I need to enclose the entire space