Kim's teacher has marked this problem as one to recheck, but Kim cannot determine what she has done incorrectly. Identify Kim's error and write a correct solution.
Six less than 2 times a number is 50. What is the number?
2x – 6 = 50 (line 1)
2x – 6 – 6 = 50 – 6 (line 2)
2x = 44 (line 3)
2x ÷ 2 = 44 ÷ 2 (line 4)
x = 22 (line 5)
2 x - 6 = 50
The error is in line 2.
6 should be added on both sides of the equation, not subtracted.
2 x - 6 + 6 = 50 + 6
2 x = 56
x = 56 / 2
x = 28
Kim's error is in line 2, where she subtracts 6 from both sides of the equation instead of subtracting 6 from the right side only.
To write a correct solution, we need to subtract 6 from both sides of the equation in line 1, not just the left side:
2x - 6 = 50
2x - 6 + 6 = 50 + 6
2x = 56
Then in line 4, we should divide both sides of the equation by 2 to isolate the variable x:
2x ÷ 2 = 56 ÷ 2
x = 28
So, the correct solution is x = 28.