IBEW Solving Linear Equations 3 — Questions and Answers
Question 1: Solve for x: 4x + 9 = 29
- x = 5 (Correct answer)
- x = 9.5
- x = 4
- x = 38
Correct answer: x = 5
Subtract 9 from both sides: 4x = 20, then divide by 4: x = 5.
Question 2: If a wire is cut into two pieces where one piece is twice as long as the other and the total length is 48 feet, how long is the shorter piece?
- 16 feet (Correct answer)
- 24 feet
- 12 feet
- 32 feet
Correct answer: 16 feet
Let x = shorter piece; x + 2x = 48, so 3x = 48, x = 16 feet.
Question 3: Solve for x: 7 - 2x = 3
- x = 2 (Correct answer)
- x = 5
- x = -2
- x = 4
Correct answer: x = 2
Subtract 7 from both sides: -2x = -4, then divide by -2: x = 2.
Question 4: Solve for t: t/3 - 4 = 2
- t = 18 (Correct answer)
- t = 6
- t = 2
- t = 24
Correct answer: t = 18
Add 4 to both sides: t/3 = 6, then multiply by 3: t = 18.
Question 5: An electrician charges a $75 service fee plus $45 per hour. A customer is billed $255. How many hours did the job take?
- 4 hours (Correct answer)
- 3 hours
- 5 hours
- 6 hours
Correct answer: 4 hours
Set up 45h + 75 = 255, so 45h = 180, h = 4 hours.
Question 6: Solve for x: 6x - 4 = 2x + 12
- x = 4 (Correct answer)
- x = 2
- x = 8
- x = 1
Correct answer: x = 4
Subtract 2x: 4x - 4 = 12, add 4: 4x = 16, divide: x = 4.
Question 7: Solve for m: 3(m - 2) = 15
- m = 7 (Correct answer)
- m = 5
- m = 3
- m = 9
Correct answer: m = 7
Divide by 3: m - 2 = 5, then add 2: m = 7.
