If 0, then 500, if 100, then 1200. How can I find X?

Question

Mathematics

I'm already dumb. Help solve:
If a=0, then b=500;
If a=100, then b=1200;
How to find b from any value of a?

Answer 1

you have two points:
first: x[1] = 0, y[1] = 500
second: x[2] = 100, y[2] = 1200
general equation of a straight line:
substitute, we get:
simplify:
Substitute x into the resulting equation - you get y

Answer 2

b = 500 + a * 7(OMG)

Answer 3

An infinite number of answers. With how many curves can you connect two points? Here is your answer.