Question

Given the equation 2x+y=7, (a) What is the value of x, when the value of y is 3? (b) What is the value of y, when the value of x is 4? (c) Find one more solution for the above equation.

Answer 1

(b) f[x]=2x+y=7 
      f[4]=2[4]+y=7
      =8+y=7
      =y=7-8
      =y=-1
(a)  f[y]=2x+y=7
       f[3]=2x+3=7
       2x=7-3
       2x=4
       x=4÷2
         x=2
(c)if x=9.then,
     2[9]+y=7
     18+y=7
      y=7-18
       y=-11