2. Find the equation?

Question

in the slope -intercept form, of the line that passes through the points (-7,-2) and (-4,1)???

Please help struggling

Answer 1

Slope - intercept form is the form of equation

y = Mx + C

where M is the slope (see prev answer) and C is the y-intercept (ie where the line cuts the y-axis if x = 0)


{well the wiki page on linear equation calls it y = Mx + B, but I was always taught y = Mx + C ... doesn't really matter what you're going to call the y-intercept and old habits die hard}


So ... Slope = rise over run

ie.

(1 - (-2)) / (-4 - (-7))

= (1+2) / (-4 + 7)
= 3/3
= 1

so ... y = x + C {because M = 1}

it's pretty easy to solve for C because you have 2 examples of x and y

-7 = -2 + C
C = -5


or

-4 = 1 + C
C = -5


So you have y = x - 5