Question

How do you solve `\sqrt { b - 7} = 4`?

Answer 1

`b = 23`

Explanation:

First, square both sides.

`(sqrt(b-7))^color(blue)(2) = 4^color(blue)(2)`

By doing this, we eliminated the square root. Now add `7` to both sides to isolate the `b` variable.

`b cancel(- 7 color(green)(+7)) = 4^color(blue)(2) color(green)(+7)`

Now simplify the other side by squaring the `4` and then adding `7` to it.

`b = (4*4) + 7`

`b = 16 + 7`

`b = 23`