word problem

Question

use the 5 step process to write and solve a system of equations

 

 

you have a 5% acetic acid solution and a 10% acetic solution but need 3 milliliters of 7% acetic solution. how many milliliters of each solution should you use?

Answer 1

You sure have many word problems :)

Ok again we use some algebra translation

n= number of milliliter of acetic solution

m= number of milliliter of acetic acid solution

from the givens we know

n+m=3 (needed milliliter of the solution)

0.05m+0.1n=0.07(3)

n+m=3

0.05m+0.1n=0.21

clean the equations little bit

n+m=3

5m+10n=21

multiply first one by -5

-5n-5m=-15

5m+10n=21

=========

5n=6

n=1.2 milliliter

find m now

1.2+m=3

m=1.8 milliliter

check

0.05(1.8)+0.1(1.2)=0.21

checks nicely!