Question 185192
.20x+.10(45-x)=45*.18
.20x+4.5-.10x=8.1
.10x=8.1-4.5
.10x=3.6
x=3.6/.1
x=36 liters of 20% acid is used.
45-36=9 liters of 19% acid is used.
Proof:
.20*36+.1*9=45*.18
7.2+.9=8.1
8.1=8.1