substitution and addition

Question

samuel buys 2 cans of paint and a roller for $30. then, he goes back to the store and buys 3 more cans of paint and 2 more rollers for $50. x=cans; y=rollers. Use Ax+By=C

Answer 1

The two equations we can make from the given information are:

2x + y = 30

3x + 2y = 50

We then can use substitution or elimination to solve. We can easily eliminate by multiplying the top equation by (-2), so we'll take that route. That gives us:

-4x -2y = -60

3x +2y = 50

Now we add down and get -1x = -10. Divide by -1 on both sides to get x = 10

Now we want to plug in that answer into one of the original equations to get the y value. We'll use the 2x + y = 30. That will give us:

2(10) + y = 30

20 + y = 30

y = 10

Hope that helps!

Answer 2

2x+y=$30

3x+2y=$50

+=

5x+3y=$80