Answer:
c) infinite
Step-by-step explanation:
z - y = 12
-3z + 3y = -36
simplify the first equation to find z in terms of y
z - y = 12
add 12 to both sides of the equation
z - y + y = 12 + y
z = 12 + y
now, substitute z for 12 + y in the second equation.
-3z + 3y = - 36
-3(12 + y) + 3y = -36
-36 -3y + 3y = -36
-36 = - 36
the answer is infinite solutions, because no matter what y and z are, -36 will always equal -36
