9:Using the substitution method, Vito is solving the following system of
equations algebraically:
y + 3x = -4
2x - 3y = -21
-Which equivalent equation could Vito use?
(1) 2(-3x – 4) + 3x = -21
(3) 2x - 3(-3x – 4) = -21
(2) 2(3x – 4) + 3x = -21
(4) 2x - 3(3x - 4) = -21