not understanding how to do this. can someone help?

Write an equation in slope intercept form of the line that passes through (4, 1) and (5, -1).
A. y = -4x + 1
B. y = -1/2 x + 9
C. y = 4x + 1
D. y = -2x + 9

Question

not understanding how to do this. can someone help?

Write an equation in slope intercept form of the line that passes through (4, 1) and (5, -1).
	A.	y = -4x + 1
	B.	y = -1/2 x + 9
	C.	y = 4x + 1
	D.	y = -2x + 9

anonymous · Answer

1) Find slope.
$$Slope = \frac{ y2 - y1 }{ x2 - x1 }$$$$Slope = \frac{ -1 - 1 }{ 5 - 4 } = \frac{ -2 }{ 1 } = -2$$
So you have a slope of -2.
You also have a given point.

2) Put into Point-Slope form. 
$$y - y1 = m(x - x1) $$ Lets use point (4, 1) and the slope of -2.
$$y - 1 = -2(x - 4)$$3) Change into Slope-Intercept form.
$$y - 1 = -2(x - 4)$$Distribute.$$y - 1 = -2x + 8$$Add 1 to both sides.$$y = -2x + 9$$

Slope-intercept form is: $$y = -2x + 9$$

anonymous · Answer

oooh thank you so much for showing me how to do this. i think im getting to know how to do it better now. thank you again!

anonymous · Answer

You're welcome! I'm glad this helped you!(:
Also:$$ \Huge{\color{turquoise}{\mathbb{Welcome \quad To \quad OpenStudy!!}}} $$

anonymous · Answer

yes it truly did help. thank you