Question

Solving a percent makes your prom using a system of linear equations

Answer 1

Water :60 ounces

Salt solution:60 ounces

Explanation

Step 1

set the equations

Let x represent the amoun of water forthe solution

let y represents the amount of solution ( 40% salt)

so

a)the scientific mixes water with the solution to obtain 120 ounces, so

$x+y=120\Rightarrow equation\left(1\right)$

b)the mixture is 20% salt

so

salt fromwater+salt from solution( 40%) = salt in the solution (20%)

so

$\begin{gathered} 0+0.4y=120*0.2 \\ 0.4y=24 \\ divide\text{ both sides by 0.4} \\ \frac{0.4y}{0.4}=\frac{24}{0.4} \\ y=60 \end{gathered}$

hence, the amount of salt solution is 60 ounces

,now to find x, replace the y value in equation (1)

$\begin{gathered} x+y=120\Rightarrow equation\left(1\right) \\ x+60=120 \\ subtract\text{ 60 in both sides} \\ x+60-60=120-60 \\ x=60 \end{gathered}$

so, water : 60 ounces

therefore, the answer is

Water :60 ounces

Salt solution:60 ounces

I hope this helps you