Question

4a+4b-5, 2a-3b+c, -3a+2b-5 subtract a-3b+7

Answer 1

7a+4b+c = 51

3a+4b+5c = 15 Subtract both,

4a-4c = 36 => a-c = 9 => a = 9+c.

Now put this in any equation, you will get=>

7(9+c) + 4b + c = 51 => 63 + 8c + 4b = 51 => 4b+8c = -12 => b+2c = -3 =>

b = -(3+2c)

a + b+ c = 9+c -3–2c + c = 6.

Hope it helps.