Practice!

Sample Problem

What is the equation of a line that passes through the points (-6, 0.8) and (4, 1.2)? (Give your answers in exact decimals)

y=x+

Solution

Slope= (y2-y1)/(x2-x1) so the slope of this line is (1.2-0.8)/(4-(-6))= 0.4/10=0.04=1/25

Now that we have a slope, we can use point-slope form to calculate the equation of this line.

(y-y1) = m(x-x1)

(y-1.2)=0.04(x-4)

y-1.2=0.04x-0.16

y=0.04x+1.04

(0.04=1/25 ; 1.04=26/25)