A student bought a calculator and a textbook for a course in algebra. He told his friend that the total cost was $115 (without tax) and that the calculator cost $20 more than four times the cost of the textbook. What was the cost of each item? Let x = the cost of a calculator and y = the cost of the textbook.

Question

A student bought a calculator and a textbook for a course in algebra.  He told his friend that the total cost was $115 (without tax) and that the calculator cost $20 more than four times the cost of the textbook. What was the cost of each item? Let x = the cost of a calculator and y = the cost of the textbook.

kingbowzer · Answer

if x = cost of a calculator and y = cost of the textbook, what does x + y represent?  also, how does x relate to y (based on the information in the question)?

anonymous · Answer

x+y=115
x=4y+20
Solve the system by using the method of substitution.

anonymous · Answer

I think the answer is 96, 19 ??

kingbowzer · Answer

if calculator = $96 and textbook = $19, that totals $115.  also, 96 = 4 * 19 + 20.  well done