Explanation:
What is the error?
The error was when the student was Substracting 10 from both sides instead of adding 10 to both sides
What should have the student have done instead?
The student would have added 10 to both sides in the equation 20= 5x – 10 to work the equation out successfully
Work the problem correctly.
20 = -8 + 5x - 2
Collect like terms
20 = 5x +(-2-8)
20 = 5x + (-10)
20 = 5x - 10
Add 10 to both sides
20 + 10 = 5x - 10 + 10
30 = 5x
Flip equation
5x = 30
Divide both sides by 30
5x/5 = 30/5
x = 6