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5 votes
Problem

1. 2(x-3)=5
2x-3=5
+3 +3
2x=8
2 2
x = 4
What is the
error?
What should the
student have done
instead?
Work problem
correctly.

1 Answer

2 votes

Explanation:

What is the error?

The error was at the beginning when trying to multiply x-3 in bracket by 2 in equation 2(x-3)=5

where instead of 2(x-3) = 2x - 6 he/she wrote 2(x-3) = 2x-3 the mistake was the student didn't multiply 2•3

What should the student have done instead?

The student would have multiplied 2•3 which is 6, then write 2x - 6 = 5 and continued question successfully

Work problem correctly.

2(x-3)=5

2x - 6 = 5

2x - 6 + 6 = 5 + 6

2x = 11

x = 11/2

x = 5.5

User Jose Sutilo
by
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