Question

If the answer to a maths question is 4,

John says the answer is: 4x + 4 + 7x = 48
Mike says the answer is: 2x + 3 = 11
Henry says the answer is: 8x + 7 = 71

Then who is/are correct? Is anyone wrong? Show workout.

Answer 1

John’s is correct
4x+4+7x=48
11x+4=48
-4 -4
11x=44
x=4

Answer 2

John and Mike are correct, Henry is incorrect.

Explanation:

Try to find x = 4 for all the equations to find out who is correct.

John:

4x + 4 + 7x = 48

Combine like terms.

11x + 4 = 48

Subtract 4 from both sides.

11x = 44

Divide both sides by 11.

x = 4

John is correct.

Mike:

2x + 3 = 11

Subtract 3 from both sides.

2x = 8

Divide both sides by 2.

x = 4

Mike is correct.

Henry:

8x + 7 = 71

Subtract 7 from both sides.

8x = 64

Divide both sides by 8.

x = 8

Henry is incorrect.