SOLUTION: A student bought a calculator and a textbook for a course in algebra. He told his friend that the total cost was $160 (without tax) and that the calculator cost $20 more than four

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Question 1195906: A student bought a calculator and a textbook for a course in algebra. He told his friend that the total cost was $160 (without tax) and that the calculator cost $20 more than four times the cost of the textbook. What was the cost of each item
Answer by math_tutor2020(3817) About Me  (Show Source):
You can put this solution on YOUR website!

x = cost of the textbook
4x = four times the cost of the textbook
4x+20 = twenty more dollars added to the previous amount
4x+20 = cost of the calculator

The textbook costs x dollars.
The calculator costs 4x+20 dollars.
These two items add to a total cost of $160 before tax.

textbook + calculator = total
(x) + (4x+20) = 160
5x+20 = 160
5x = 160-20
5x = 140
x = 140/5
x = 28
The textbook costs $28

4x+20 = 4*28+20 = 112+20 = 132
The calculator costs $132

The total cost is 28+132 = 160 to confirm our answers.

Answers:
textbook = $28
calculator = $132

Side note: Desmos and GeoGebra are free online calculators that have far more features than anything a TI83 or TI84 can do. Also, they are much faster. The only drawback is that in formal test environments (eg: SATs), such online calculators are not allowed.