MATH SOLVE

7 months ago

Q:
# PLEASE HELP ME!A pharmacist has a 12% boric acid solution and a 20% boric acid solution. How much of each must he use to make 80 grams of a 15% boric acid solution?

Accepted Solution

A:

x = amount of
20% solution needed

80 grams - x = amount of 12% solution needed

20% = 0.2012% = 0.12 15% = 0.15 Write out the equation:

0.20xΒ + 0.12(80-x) = 0.15(80) Distribute the part in parenthesis:

0.20x + 9.6 - 0.12x = 12 Subtract 9.6 from each side and combine like terms: 0.20x - 0.12x = 12 - 9.6

0.08x = 2.4 Divide both sides by 0.08:

x = 2.4/0.08

x = 30 grams of the 20% solution

80 - 30 = 50 grams of the 12%

80 grams - x = amount of 12% solution needed

20% = 0.2012% = 0.12 15% = 0.15 Write out the equation:

0.20xΒ + 0.12(80-x) = 0.15(80) Distribute the part in parenthesis:

0.20x + 9.6 - 0.12x = 12 Subtract 9.6 from each side and combine like terms: 0.20x - 0.12x = 12 - 9.6

0.08x = 2.4 Divide both sides by 0.08:

x = 2.4/0.08

x = 30 grams of the 20% solution

80 - 30 = 50 grams of the 12%