A+b-c = 170 B+c-A = 130

solve

The correct answer is A = 110, B = 40, C=20 ...

Explanation

If A+B-C = 170 and B+C-A=130,

=C+A = 130

or, C = 130 - A

Again, A+B-C = 170

or, A+B = 170+C

A+B = 170+130-A (c=130-A)

A+B = 300-A

2A+B = 300

A+B = 300/2

A+B = 150

A+B-C = 170

A+B = 170+C

150 = 170 + C (A+B = 150)

or, C = 20 ... (1.)

A+C = 130

or, A + 20 = 130 (A=110) ... (2)

A+B = 150

110+B = 150

B = 150-110

B = 40 ... (3)

Therefore, A = 110, B = 40, C=20 ...