Question

Statement
4x = 7x - 21

Reason
?

Answer 1

4x = 7x -21
4x - 7x = -21
-3x = -21
X = 7

Check your work for your reason
4(7) = 7 (7) -21
28 = 49-21
28 = 28
They equal

Answer 2

solution;

21=7x-4x

21=3x

21x/3x

Then finalay aneswer is 7x