For the following system, if you isolated x in the first equation to use the substitution method, what expression would you substitute into the second equation? −x − 2y = −4 and 3x + y = 12 a.) −2y − 4 b.) 2y − 4 c.) 2y + 4 d.) -2y + 4

Type the correct answer in the box. consider the system of linear equations below. rewrite one of the two equations above in the form ax + by = c, where a, b, and c are constants, so that the sum of the new equation and the unchanged equation from the original system results in an equation in one variable.