use matrix addition to solve this equation
_ _ _ _
| 3 1 0 | | 5 2 -4 |
c= | -1 2 4 | + | 1 12 3 |
L 9 7 -2_| | 11 3 -2 _|

c11=

c31=

c22=


someone please help!!!!
99 points!!