12+2x-10=3x-5
12-10 +2x=3x-5
2+2x=3x-5
Move +3x to the other side. Sign changes from +3x to -3x.
2+2x-3x=3x-3x-5
2+2x-3x=-5
2-x=-5
Move +2 to the other side. Sign changes from +2 to -2.
2-2-x=-5-2
-x=-7
Multiply by -1 for -x and -7
(-1)(-x)=(-1)(-7)
x=7
Answer: x=7
