Do 9+4 because you need to get m alone. you get 13 plug 13 in for m (13-4=9) and then 9=9
Just use the coefficients for each variable and put it in a matrix. Is the second question set equal to something? Because then you would put it in place as the question mark. (Did the pic come through?)
So the 3x3 matrix is made up of the coefficients and then to augment the matrix, you add another column at the end with the solutions. Good luck!
Answer:
2.873375
Step-by-step explanation:
Let n be the number 18=60% of n
18=0.6n
18/0.6=n
30=n