(a+b):(2c-a-b) если а+b=-1 а с=3

Question

(a+b):(2c-a-b) если а+b=-1 а с=3

Answer 1

2c -a -b = 2c -(a+b)

(a+b) : (2c -(a+b)) = -1 /(2*3 -(-1)) =

= -1 /(6 +1) = -1/7