If three times a number is decreased by 5, the result is 7. Find the number.
IS THIS RIGHT ?
3x -5 = 7
+5 +5
__________
3x = 12
___ ____
3 3
x=4
IS THIS CORRECT
You can always do a simple check of your answer, without redoing the derivation.
3x4 - 7 = 5.
Therefore, your answer is correct.