Question

The points (-1.6, 2.7) and (3.2, 7.98) are on the graph of a linear relationship between two variables, r and y.

(3.2,7981
(-1.6,22
Write a formula that expresses y in terms of x.
Preview
c. What is the value of y when x= 114?

Answer 1

y = 1.1x +4.46

y = 129.86 for x = 114

Explanation:

The two-point form of the the equation for a line is useful for this.

y = (y2 -y1)/(x2 -x1)(x -x1) +y1

y = (7.98 -2.7)/(3.2 -(-1.6))(x -(-1.6)) + 2.7

y = 5.28/4.8(x +1.6) + 2.7

y = 1.1x +1.76 +2.7

y = 1.1x +4.46

__

When x=114, the value of y is ...

y = 1.1(114) +4.46

y = 129.86