Need help with linear function?

Question

the zero of the linear function S is 3. the graph of this function intersects the vertical axis at S(x)= -2. find an equation for S(x)

Answer 1

If S(x) is a linear function then it is of the form:

S(x) = Ax + B

for some constants A and B.

We are told

S(3) = 0 and S(0) = -2

=>

3A+B=0

B=-2

=>A=2/3

so S(x) = 2x/3 - 2