1. Multiply both sides by 42 (the LCM of 6 and 7)
7(w-8)=6(w-9)
2. Expand
7w-56=6w-54
3. Add 56 to both sides
7w=6w-54+56
4. Simplify 6w-54+56 to 6w+2
7w=6w+2
5. Subtract 6w from both sides
7w-6w=2
6. Simplify 7w-6w to w
w=2
7. Have a nice day ;D
I hope it helped :D