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. …

Question

asked Dec 8, 2019 145k views

1 Answer

Gravy · Answer 1 · 2019-12-13T10:14:11+0000

Answer: B. x, in the second equation

Explanation:

The given system :

$2x+6y=9...................(1)\\\\3x-12y=15.........................(2)$

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

$x-4y=5\\\\\Rightarrow\ x=4y+5$

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