Challenge Questions. I need to know the steps.

Question

You are buying $48 worth of two types of lawn seed. Ryegrass lawn seed sells for $0.70 per pound and Fescue sells for $1.15 per pound.

Define your variables and derive an equation to represent the situation.

If you bought 25 lbs of Fescue lawn seed, then how many pounds of Ryegrass lawn seed did you buy?

Answer 1

R-ryegrass

f-fescue

Ryegrass lawn seed sells for $0.70 per pound

Fescue sells for $1.15 per pound.

total cost $48

0.70r+1.15f=48

substitute 25 for f and solve for r

0.70r+1.15(25) = 48

0.70r + 28.75 = 48

subtract 28.75 from both sides

(0.70r+28.75) -28.75 = 48 - 28.75

0.70r=19.25.

divide by 0.70 on both sides

0.70r/0.70 = 19.25/0.70.

r=27.5 lbs