I bought 2 cans of paint and one roller for $30. Then i bought 3 more cans of paint 2 more rollers for $50. How much was it for a roller?

Question

How much is it for one roller?

 

Answer 1

Let paint = p and rollers = r

 

1. Setup equations

2p + r = 30 and 3p + 2r = 50

 

2. Solve the first equation for r

r = -2p + 30

 

3. Substitute Step 2 into the leftover equation

3p + 2(-2p + 30) = 50

 

4. Simplify

3p - 4p + 60 = 50

-p + 60 = 50

 

5. Solve for "p"

 

6. Plug Step 5 into 3p + 2r = 50 to solve for the cost of the rollers.

Answer 2

Hi Amber,

 

Let's set thisup.

 

P = can of paint

R = roller

 

From the first sentence

2P + R = 30

 

From the 2nd sentence

3P + 2R = 50

 

Let's put them together

2P + R = 30

3P + 2R = 50

 

If we used the elimination method to solve, we will need to eliminate one variable.

Multiply the 1st equation by -2

-4P - 2R = -60

3P + 2R = 50

 

Add these two equations together

 

-P = -10

P=10

 

And using the first equation, we substitute 10 in for P and solve for R

2(10) + R = 30

R = 10

 

A roller is $10