9.
8x-10=x+11
subtract x and add 10 to both sides so that all the x’s are on one side and the numbers on the other
7x=21
Divide both sides by 7 to isolate x
x=3
10.
5x-7=7x-17
Do the same thing as above subtract the 7x and add 7
-2x=-10
divide by -2
x=5