Answer:
The value of A is -3x, the value of B is 14x and the value of C is -21. A and B are like terms.
Explanation:
From the given table it is noticed that the values in first row are x and 7. The values in first column are 2x and -3.
Multiply each row value with column values.




The value of A is -3x, the value of B is 14x and the value of C is -21.
Two terms are called like terms if they have same variables with same power.
Since A and B have variable x with degree 1 but C is constant, therefore A and B are like terms.