Question

If x=a and y=b is the solution of the equations x-y=2 and x+y =4 then the value of a and b are, respectively


( A ) 3 and 5 
( B ) 3 and 1 
( C ) 5 and 3 
( D ) -1 and -3

Answer 1

x=a y=b
x-y=a-b=2
a=b+2 ------------(1)
x+y=a+b=4---------------(2)

Sub (1) into (2)
b+2+b=4
2b=2
b=1

a=b+2
  =1+2
  =3
a=3, b=1

Answer 2

if we look around.
b) and d)
both are possible.