A carpenter purchased 70 ft of redwood and 90 ft of pine for a total cost of $323. A second purchase, at the same prices, included 100 ft of redwood and 50 ft of pine for a total cost of $375. Find the cost per foot of redwood and of pine.

Question

wolf1728 · Answer

70R + 90P =$323
100R + 50P $375
There's your equations.
Solve and get your answers.

candycanegone · Answer

how do i solve?

candycanegone · Answer

like 170r + 140p ?

wolf1728 · Answer

No- you first have to eliminate an unknown.
I messed up - will have to start over

candycanegone · Answer

it's okay i got it! :)

candycanegone · Answer

thank you!

wolf1728 · Answer

a) 70R + 90P =$323 
b) 100R + 50P $375

Multiplying equation b by -.7
b) -70R -35P = -262.50

Now, add equation a + b
a) 70R + 90P =$323
b) -70R -35P = -262.50

55P = 60.50

P = 1.10
The cost of pine

wolf1728 · Answer

and to solve for price of redwood
a) 70R + 90*1.10 =$323 

70R = 323 - 99
70R = 224
R = 3.20 price of redwood