Question 20) write a linear function f with f (0) = 7 and f (3) =
question 21) write a linear function f with f (4) = f (0) = -2
question 22) write a linear function with f with f (5) = -1 and f (0) = -5

y = -2

y=x - 5

Step-by-step explanation:

Let y=mx +  c

So f(4)=-2

this gives, -2=4m+c      -----------eq 1

Also f(0)=-2

This gives -2=c.            --------------eq2

Putting value of c in equation in eq1 we get m=0.

So y=-2.

For the third question,

let y=mx + c

f(0)=-5

this gives, c = -5.

f(5)= -1

this gives -1 =5m -5.

              => 4=5m

              => m=

So y=x - 5