Answer:
8 units
Step-by-step explanation:
1) x(x+7)
3) (x+5)*(x+4)
4) (x-6)*(x-8)
5) x(2x+21)+11
6) 5(a-5)*(a+5)
7) (4x+3)*(2x-3)
8) 4( x²-6xy+8)
5x(5x+1)^2
= 5x(25x^2+10x+1)
= 125x^3+50x^2+5x