ANSWER:
20
STEP-BY-STEP EXPLANATION:
We have the following equation:
[tex]c^2+4r-3\cdot(r-c)[/tex]
We simplify and we have the following:
[tex]\begin{gathered} c^2+4r-3r+3c=c^2+r+3c \\ c=2,r=10 \\ \text{ replacing} \\ 2^2+10+3\cdot2=4+10+6=20 \end{gathered}[/tex]
