The following system of equations is given below:


\large -5x+y=-18


\large -10x-5y=20


Which of the following steps is not suitable to solve this system by elimination?


a. Multiply the first equation by 2 and then subtract the equations from each other.

b. Multiply the first equation by -5 and then add the equations together.

Selected:c. Multiply the first equation by 5 and then add the equations together.This answer is incorrect.

d. Multiply the first equation by -2 and then add the equations together.