What is the y intercept for a line with point (12,-7) slope 5/2?

1 Answer
Oct 2, 2015

y-intercept: (-37)(37)

Explanation:

Step 1: Write equation in "point-slope form"
The point-slope form for a line with a slope of mm through a point (hatx,haty)(ˆx,ˆy) is
color(white)("XXX")(y-haty) = m(x-hatx)XXX(yˆy)=m(xˆx)

For the given slope and point, this becomes
color(white)("XXX")(y+7)=5/2(x-12)XXX(y+7)=52(x12)

Step 2: Convert to "slope-intercept form"
The slope-intercept form for a line with slope mm and y-intercept bb is
color(white)("XXX")y=mx+bXXXy=mx+b

Starting with
color(white)("XXX")y+7 = 5/2(x-12)XXXy+7=52(x12)

color(white)("XXX")y+7 = 5/2x-30XXXy+7=52x30

color(white)("XXX")y=5/2x-37XXXy=52x37
which is the "slope-intercept form with y-intercept -37#