Answer:
B = Blue paint = 3.5 gallons
Y= Yellow paint = 24.5 gallons
Explanation:
Let B = Blue paint
Y= Yellow paint
Your mixing blue paint and yellow paint to get a total of 28 gallons.
B + Y = 28 gallons
You want to use 7 times yellow paint as blue.
This means, 7B = Y
How many gallons of each should you use ?
Hence,
B + Y = 28
B + 7B = 28
8B = 28
B = 28/8
B = 3.5 gallons
B + Y = 28 gallons
Y + 3.5 gallons = 28 gallons
Y = 28 gallons - 3.5 gallons
Y = 24.5 gallons
B = Blue paint = 3.5 gallons
Y= Yellow paint = 24.5 gallons