Question

If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the second equation is substituted into the first equation.
2x – 5y = –3
6x – 3y = –3 ...?

Answer 1

If you were to use the substitution method to solve the following system, we need to write one of the equation to an expression equivalent to y. Let us say the second equation, we write it as follows:

6x – 3y = –3
-3y = -6x - 3
y = 2x + 1

We substitute the equation to the first given equation as follows:

2x – 5y = –3
2x – 5(2x + 1) = –3
2x - 10x - 5 = -3
-8x = 2
x = -1/4
y = 2(-1/4) + 1 = 1/2