Question

7(x-8)-8(x-7)=x+7-(x-3)

Answer 1

-x=10
x=-10, just combine like terms!

Answer 2

remeber, you can do anything to an equation as long as you do it to both sides
also, -(x-3) means -1(x-3), don't forget to distribute

so distribute first

7x-56-8x+56=x+7-x+3
combine like terms
-x=10
x=-10
wow, that simplified fast