Question

The total cost of four pens and seven mechanical pencils is $13.25. The cost of each pencil is .75 cents. Write an equation to find out the cost of each pen

Answer 1

X = pens and y = pencils

4x + 7y = 13.25
y = 0.75

4x + 7(0.75) = 13.25 
4x + 5.25 = 13.25
4x = 13.25 - 5.25
4x = 8
x = 8/4
x = 2 <===so each pen cost 2 bucks