I have no idea how to do this: Slope= -3, y-intercept= -1 its slope-intercept form


Slope= -2, y-intercept= -4


Through: (-3,2) , slope=-1/3


Through: (3,2) and (0,-5)


x-5y-5=0

Verified Answer :

iGreen

Slope-intercept form is \(\sf~y=mx+b\), where \(\sf~m\) is the slope and \(\sf~b\) is the y-intercept.

Slope = -3, y-intercept = -1

Plug in what we know:

\(\sf~y=mx+b\)

\(\sf~y=-3x-1\)

Slope = -2, y-intercept = -4

Plug in what we know:

\(\sf~y=mx+b\)

\(\sf~y=-2x-4\)

Through: (-3,2) , slope=-1/3

Okay, here we use point-slope form, and the simplify to get it in slope-intercept form.

\(\sf~y-y_1=m(x-x_1)\)

Where \(\sf~y_1\) is the y-value of the point, \(\sf~x_1\) is the x-value of the point, and \(\sf~m\) is the slope.

Plug in what we know:

\(\sf~y-2=-\dfrac{1}{3}(x+3)\)

Distribute -1/3 into the parenthesis:

\(\sf~y-2=-\dfrac{1}{3}x-1\)

Add 2 to both sides:

\(\sf~y=-\dfrac{1}{3}x+1\)

Through: (3,2) and (0,-5)

Now we plug this into the slope-formula to find the slope, plug the slope and one of these points into point-slope form, then simplify to get it in slope-intercept form.

\(\sf~m=\dfrac{y_2-y_1}{x_2-x_1}\)

(3, 2), (0, -5)
x1 y1 x2  y2

Plug in what we know:

\(\sf~m=\dfrac{-5-2}{0-3}\)

Subtract:

\(\sf~m=\dfrac{-7}{-3}\)

\(\sf~m=\dfrac{7}{3}\)

Plug this into point-slope form along with any point.

\(\sf~y-y_1=m(x-x_1)\)

\(\sf~y-2=\dfrac{7}{3}(x-3)\)

Distribute 7/3 into the parenthesis:

\(\sf~y-2=\dfrac{7}{3}x-7\)

Add 2 to both sides:

\(\sf~y=\dfrac{7}{3}x-5\)

x-5y-5=0

Add 5 to both sides:

\(\sf~x-5y=5\)

Subtract 'x' to both sides:

\(-5y=-x+5\)

Divide -5 to both sides:

\(\sf~y=\dfrac{1}{5}x-1\)