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!
To solve this we are going to use the formula for the area of a circle:

where

is the area of the circle

is the diameter of the circle
We know from our problem that the area of our circle is 10 inches long, so

. Lets replace that value in our formula to find

:


We can conclude that the correct answer is: 78.54 square inches, or in centimeters: 506.7 square cm.
Step-by-step explanation:
12:18
12 to 18
12/18 = 2/3