Question

Which expression is equivalent to 7a³ (8a² + a)²-4a³?
Simplify.

Answer 1

`7a³ (8a² + a)²-4a³ \\ \\ 7 {a}^(3)(8 { {a}^(2) + a)(8 {a}^(2) + a )} - 4 {a}^(3) \\ \\ 7 {a}^(3) ( {8a}^(2) (8 {a}^(2) + a ) + a(8 {a}^(2) + a ) - 4 {a}^(3) \\ \\ 7 {a}^(3) (64 {a}^(4) + 8{a}^(3) + 8 {a}^(3) + {a}^(2) ) - 4 {a}^(3) \\ \\ 7 {a}^(3) (64 {a}^(4) + 16 {a}^(3) + {a}^(2) ) - 4 {a}^(3) \\ \\ 448 {a}^(7) + 112 {a}^(6) + 7 {a}^(5) - 4 {a}^(3) \\ \\ {a}^(3) (448 {a}^(4) + 112 {a}^(3) + 7 {a}^(2) - 4).`