Interimmediate alegbra

Question

How many bleach mililiters of a 2% bleach solution must be mixed with a 10% bleach solution tp produce 800 'll of a 3% bleach solution. How many of ml of 2% bleach solution is needed?

Answer 1

x=ml of 2% and y=ml of 10%

x+y=800

.02x+.1y=.03*800

Multiply the 2nd equation by 100 and divide by 2:x+5y=1200

Subtract the first equation: 4y=400

and y=100 so that x =700

Use these values to check that they, in fact, solve the problem!