If you were to solve the following system by substitution, what would be the best variable to solve for and from what equation? 2x+6y=9 3x-12y=15 a. y, in the first equation b. x, in the second equation c. x, in the first equation d. y, in the second equation

B.x, in the second equation

Step-by-step explanation:

The given system :

To apply the substitution method , first we need to select the best variable and  a equation which is easy to simplify.

From the given system equation (2) have all the numbers which are multiples of 3.

Then we divide 3 on both sides of equation (2), we get

Therefore, the best variable to solve for and from what equation is x, in the second equation.