it's important do do the same thing to both sides so the equation will stay equal
exg
3=3
multipy 4
12=12
still true
so 3d+8=2d-17
2d means 2 times d or d+d
so
3d+8=2d-17
subtract 2d from both sides
3d-2d+8=2d-2d-17
d+8=-17
subtract 8 from both sies
d=-25
d=-25
