PLEASE HELP ME. ANSWER NUMBERS 4 LETTER C ONLY. AND NUMBER 7. WITH SOLUTIONS THANK YOU

4. For each matrix, continue the appropriate row operations to convert the matrix to its RREF and describe the solution set of the original system. O Co -4 9 0 4 0 7 0 ( c) (a) ( b ) -7 Oo 0 2 0 0 7. Use any method to find the inverses of 1 2 9 and and generalize a formula for the A 0 0 2 0 inverse of 1 2 3 ...ooo . . . 1 2 3