# How do you simplify the expression 1+7sqrt(z-1) for z=290?

Feb 18, 2017

$120$

#### Explanation:

Substitute z = 290 into the expression.

$1 + 7 \sqrt{\textcolor{red}{290} - 1}$

$= 1 + 7 \sqrt{289}$

$= 1 + \left(7 \times 17\right) \text{ since } \sqrt{289} = 17$

$= 1 + 119$

$= 120$