Option B is the odd one out
I think it would be D, because you would divide the 1/8 be 5, giving you 1/40
5x+9 = 10x-9
Take 5x from both sides
9 = 5x-9
Add 9 to both sides
18 = 5x
Divide by 5
3.6=x
I think the answer is 22mn2+66m2n-64 since there are no more like terms