Question

If `4-3a=7-2(2a+5)`, what is `a^2+7a`?

Answer 1

`0`

Explanation:

We have: `4 - 3 a = 7 - 2 (2 a + 5)`

`=> 4 - 3 a = 7 - 4 a - 10`

`=> 4 - 3 a = - 3 - 4 a`

`=> a = - 7`

Then, `a^(2) + 7 a = (- 7)^(2) + 7 (- 7) = 49 - 49 = 0`