Linear Equations in One Variable Flashcards

If 3(x + 4) = 5x − 2, what is x?

Answer: 7

3x + 12 = 5x − 2 → 14 = 2x → x = 7.

A savings account earns $15 per month in interest. After 8 months the account has $320. What was the initial balance?

Answer: $200

P + 15(8) = 320 → P + 120 = 320 → P = 200.

Solve for x: 5x − (x + 2) = 2(x + 5)

Answer: 6

4x − 2 = 2x + 10 → 2x = 12 → x = 6.

For what value of c does the equation 2x + c = 5x − 9 have the solution x = 5?

Answer: 6

2(5) + c = 5(5) − 9 → 10 + c = 16 → c = 6.

Kai has $150 in a bank and withdraws $12 each week. After w weeks he has $54. What is w?

Answer: 8

150 − 12w = 54 → 12w = 96 → w = 8.

Solve for x: 4(2x + 1) − 3(x − 2) = 30

Answer: 4

8x + 4 − 3x + 6 = 30 → 5x + 10 = 30 → 5x = 20 → x = 4.

A number is 5 less than three times another number. If the larger number is 22, what is the smaller number?

Answer: 9

3n − 5 = 22 → 3n = 27 → n = 9.