Question

How Do You Solve (8x+7)^3?

Answer 1

(8x+7)*(8x+7)*(8x+7)
(8x+7)(64x^2+112x+49)
(8x)(64x^2)+(8x)(112x)+(8x)(49)+(7)(64x^2)+(7)(112x)+(7)(49)
512x^3+896x^2+392x+448x^2+784x+343
Answer:
512x^3+1344x^2+1176x+343

Answer 2

I would use pascal's triangle
goes like this
0         1
1        1 1
2       1 2 1
3      1 3 3 1

the numbers on the left are the power of the binomial

baseically for the third power
(a+b)^3=1a^3b^0+3a^2+b^1+3a^1+b^2+1a^0+b^3

so you have
(8x+7)^3=1(8x)^3(7)^0+3(8x)^2(7)^1+3(8x)^1(7)^2+1(8x)^0(7)^3=
512x^3+1344x^2+1176x+343