Discover new knowledge and insights with IDNLearn.com's extensive Q&A database. Get comprehensive and trustworthy answers to all your questions from our knowledgeable community members.

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. The corresponding modeling system is {x+y=115x=4y+20. Solve the system by using the method of substitution.

Sagot :

Answer:

X=$96

Y=$19

Step-by-step explanation:

x=4y+20

X+Y=$115

4Y+20+Y=$115

5Y+20=$115

-20 -20

5Y=$95

/5 /5

Y=$19

X=4 x $19 + $20

X=$76+$20

X=$96