Question

Marta is solving the equation s=2πrh+2πr^2 for h. which should be the result?

Answer 1

Answer: First option.

Step-by-step explanation:

Marta needs to subtract $2\pi r^2$ from  both sides of the equation:

$s=2\pi rh+2\pi r^2$

$s- 2\pi r^2=2\pi rh+2\pi r^2- 2\pi r^2$

$s- 2\pi r^2=2\pi rh$

Now she needs to divide both sides of the equation by $2\pi r$, then:

$h=\frac{s- 2\pi r^2}{2\pi r}$

Rewriting:

$h=\frac{s}{2\pi r}-\frac{2\pi r^2}{2\pi r}$

Simplifying, she should get:

$h=\frac{s}{2\pi r}-r$

This matches with the first option.

Answer 2

Answer:

$\frac{s}{2\pi r}-r=h$

Step-by-step explanation:

Given equation is $s=2\pi rh+2\pi r^2$.

Now we need to solve this equation for "h" and match with the given choices to find the correct choice.

$s=2\pi rh+2\pi r^2$

$s-2\pi r^2=2\pi rh$

$2\pi rh=s-2\pi r^2$

$h=\frac{s-2\pi r^2}{2\pi r}$

$h=\frac{s}{2\pi r}-\frac{2\pi r^2}{2\pi r}$

$h=\frac{s}{2\pi r}-r$

$\frac{s}{2\pi r}-r=h$

Hence first choice $\frac{s}{2\pi r}-r=h$ is correct choice.