IBEW Solving Linear Equations 5 — Questions and Answers
Question 1: Solve for x: x + 13 = 5
- x = -8 (Correct answer)
- x = 18
- x = 8
- x = -18
Correct answer: x = -8
Subtract 13 from both sides: x = 5 - 13 = -8.
Question 2: Three electricians split a job bonus equally. If each receives $240, which equation finds the total bonus B?
- B/3 = 240 (Correct answer)
- 3B = 240
- B - 3 = 240
- B + 3 = 240
Correct answer: B/3 = 240
Dividing the total by 3 gives each person's share: B/3 = 240.
Question 3: Solve for x: 8x - 5 = 6x + 9
- x = 7 (Correct answer)
- x = 1
- x = 2
- x = 14
Correct answer: x = 7
Subtract 6x: 2x - 5 = 9, add 5: 2x = 14, divide: x = 7.
Question 4: Solve for x: x/6 = 9
- x = 54 (Correct answer)
- x = 3
- x = 15
- x = 1.5
Correct answer: x = 54
Multiply both sides by 6: x = 9 × 6 = 54.
Question 5: A voltage reading is modeled by V = 12t + 4 where t is time in seconds. At what time t does V equal 52 volts?
- t = 4 seconds (Correct answer)
- t = 3 seconds
- t = 5 seconds
- t = 8 seconds
Correct answer: t = 4 seconds
Set 12t + 4 = 52, subtract 4: 12t = 48, divide: t = 4 seconds.
Question 6: Solve for p: 2p + 14 = 0
- p = -7 (Correct answer)
- p = 7
- p = -14
- p = 14
Correct answer: p = -7
Subtract 14: 2p = -14, then divide by 2: p = -7.
Question 7: A 120-volt circuit has resistance R. Using V = IR with I = 15 amps, which equation correctly solves for R?
- R = 120/15 = 8 ohms (Correct answer)
- R = 15/120 = 0.125 ohms
- R = 120 × 15 = 1800 ohms
- R = 120 - 15 = 105 ohms
Correct answer: R = 120/15 = 8 ohms
Dividing both sides of V = IR by I gives R = V/I = 120/15 = 8 ohms.
