# How do you solve sqrt(10h)+1=21 and check your solution?

Jul 11, 2018

I tried this:

#### Explanation:

Let us rearrange it and write:

$\sqrt{10 h} = 21 - 1$

$\sqrt{10 h} = 20$

square both sides:

${\left(\sqrt{10 h}\right)}^{2} = {20}^{2}$

$10 h = 400$

and:

$h = \frac{400}{10} = 40$

let us use this result in our original equation:

$\sqrt{10 \cdot 40} + 1 = 21$

$\sqrt{400} + 1 = 21$

$20 + 1 = 21$ YES

Jul 11, 2018

$h = 40$

#### Explanation:

$\sqrt{10 h} + 1 = 21$

$\sqrt{10 h} = 20$

$10 h = {20}^{2}$

$10 h = 400$

$h = 40$

To check your solution, sub $h = 40$ back into your equation

LHS
=$\sqrt{10 h} + 1$
=$\sqrt{10 \times 40} + 1$
=$20 + 1$
=$21$
=RHS

Therefore, when $h = 40$, the equation is true