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 first equation is substituted into the second equation.

15x - y = -6
5x - 3y = -13

a 5(-15x - 6) - 3y = -13
b 5(15x + 6) - 3y = -13
c 5x - 3(15x + 6) = -13
d 5x - 3(-15x - 6) = -13
Not sure how to do this...

Answer 1

i would solve for \(y\) in the first equation and get
\[y=15x+6\] then replace \(y\) by \(15x+3\) in second equation using parentheses and get
\[5x-3(15x+6)=-13\]

Answer 2

typo, meant replace \(y\) by \(15x+6\)