To check, plug in -6 for each of the x's.
5(-6) + 7 = 3(-6) -5 <<--- We hope they are equal.
-30 +7 = -18 - 5
-23 = -23 <<--- They are equal, so x = -6 is correct.
5x+7=3x-5
2x+7=-5
2x=-12 <(second and third lines) put common variables on the same side (the x's with x's whole #'s with whole #'s
then you divide by 2 to get x isolated
x=-6 (divide by -1 to get a positive answer)