The points ( − 1.8 , 2.3 ) and ( 3.5 , 8.13 ) are on the graph of a linear relationship between two variables, x and y .

Question

Write a formula that expresses y in terms of x

What is the value of y when x=118?

Answer 1

You can use the form y = mx + b, where m is the slope and b is the y=intercept (where x =0)

Use the given points to substitute in this equation...to generate 2 equations with unknowns m and b.

Here is the first one:

2.3 = (-1.8)*m + b

Use the other point to generate the 2nd equation, then solve the pair for m and b.