Question

A+b+c = 42, a+b = 24, b+c=18 find a+c

Answer 1

given ,
a+b+c=42,-------equation 1
a+b=24,----------equation 2
b+c=18,------------equation 3
then find a+c
the answer ,
let we substitute the value of equation 2 in equation 1
24+c=42 [as a+b=24]
therefore ,c=42-24=18 
c=18
again let we substitute the value of equation 3 in equation 1
a+18=42 [as b+c=18]
a=42-18=24
therefore a =24 
on the whole a+c=24+18 =42