Question

Please help me I don’t know how to solve it and will mark brainiliest

Answer 1

Answer: One plain roll is 4 dollars and one shiny roll is 6 dollars.

Step-by-step explanation:

lets start by saying

rolls of plain wrapping paper = x

rolls of shiny wrapping paper = y

Kathryn sold 4 plain rolls and 3 shiny rolls for 34 dollars.

4x+3y=34

Eugene sold 4 plain rolls and 2 shiny rolls for 28 dollars

4x+2y=28

Both equations will look like this.

4x+3y=34

-1(4x+2y)=(28)-1

we can multiply the second equation by -1 to get y alone. (doesn't matter which equation). Once you do that, the positive 4x and the negative 4x cancel out, 3y-2y=1y and 34-28=6. you are left with

1y=6 so one shiny roll is 6 dollars.

now use that price to find the cost of the plain roll.

lets use Kathryn's equation

4x + 3(6)=34

4x + 18= 34

      -18  -18

4x=16. Divide by 4 to find cost of one plain roll.

16÷4=4. One plain roll costs 4 dollars.

Lets check. Using Kathryn's equation,

4(4) + 3(6)=34

16+18=34

34=34. We are right.