Answer: 22
Step-by-step explanation:
The two matrices are equal, which means each corresponding component is equal to one another.
The bottom left corners x+1 and 10 must be equal.
x+1 = 10
x = 10-1
x = 9
This means the 1st column of the matrix on the left has these values (from top to bottom): 1, 4, 7, 10
Those values add to: 1+4+7+10 = 22