Question

(4a-9)^2

multiply and simplify completely

Answer 1

`16{a}^(2)-72a+81`

Explanation:

1) Use Square of Difference:
`{(a-b)}^(2)={a}^(2)-2ab+{b}^(2).`

`{(4a)}^(2)-2* 4a* 9+{9}^(2)`

2) Use Multiplication Distributive Property:
`{(xy)}^(a)={x}^(a){y}^(a)`

`{4}^(2){a}^(2)-2* 4a* 9+{9}^(2)`

3) Simplify
`{4}^(2)` to 16

`16{a}^(2)-2* 4a* 9+{9}^(2)`

4) Simplify
`{9}^(2)` to 81

`16{a}^(2)-2* 4a* 9+81`

5) Simplify
`2* 4a* 9` to 72a.

`16{a}^(2)-72a+81`