Ineed with this math
which equation is not equivalent to 2x + 15 = 35?
a.) 45x=845x=8
b.)2x − 5 = x + 25
c.)2x + 7 = 27
d.)43x=x+103

In order to find which one is or isn't, you need to solve for the value of 'x'. 
2x + 15 = 35 
2x = 20
x = 10 

Substitute x =10, into equation. If each side are not the same (i.e. 0=2), then that's the equation that is not equivalent,

Answer is B
Double check this. Chur! :)

Hope this makes sense.