write an equation in slope-intercept form

Question

Write an equation in slope-intercept form for the following line:

(-1,-13) and (0,19)

Answer 1

Slope of a line from 2 points is (y2 - y1)/(x2-x1)

The first point (-1, -13) has x1 = -1 and y1 = -13

The second point (0, 19) has x2 = 0 and y2 = 19

Slope = [ 19 - (-13)] / [0 - (-1) ] = (19+13)/(0+1) = 32/1 = 32

This is the SLOPE given by "m" in the slope intercept form which is y = mx + b

So now we have one of the variable we need, we have m.

Chose one of the points (I like the second point (0,19) and plug in the x (=0) and the y (=19) for the "x" and "y" in the slope intercept equation.

19 = 32(0) + b

And now we solve for b.

19 = 0 + b

so b = 19

And the slope intercept form (which keeps an "x" and a "y" in the equation) becomes

y = 32 x + 19