Use the distributive property on the parentheses, then solve accordingly.
-3(2r+7)=3
-6r-21=3
-6r=24
r=-4
Here is the answer but basically the work you just plug in 6 for A, 12 for B, and 5 for C..into the quadratic formula and solve from there
Answer:
A
Step-by-step explanation:
see attached .
hope it's helps .