Equations are equivalent when you can obtain one by subtracting, adding, dividing, or multiplying the same number on the other. 
Which of the following equations are NOT equivalent to $x+5=13$? 
Options:
[a] $x+5-5=13-5$ 
[b] $2(x+5)=26$ 
[c] $x+5-13=0$ 
[d] $x+5+13=0$ 