408,483 views
38 votes
38 votes
What is the equation of the line that passes through (4, -1)

and has a slope of -5?
A y = -5x + 19
B y = -5x + 21
C y = -5x - 19
D y = -5x – 21

User Carrington
by
2.8k points

2 Answers

22 votes
22 votes
We have y=ax+b
Substitute all the informations we have :
-1= -5(4) +b
solve for b
B = 19
A is the correct answer
User Pthalacker
by
2.5k points
19 votes
19 votes

Answer:

Explanation:

answer: y = -5 + 19

We can use the point-slope formula to find an equation to solve this problem. The point-slope formula states: (y−y1)=m(x−x1)

Where m is the slope and (x1y1) is a point the line passes through.

Susbtituting the slope and values from the point from the problem gives:

(y−−1)=−5(x−4)

(y+1)=−5(x−4)

We can also solve this for the slope-intercept form. The slope-intercept form of a linear equation is: y=mx+b

Where m is the slope and b is the y-intercept value.

Substitute the slope from the problem for m and the values of the point from the problem for x and y and solve for b:

−1=(−5⋅4)+b

−1=−20+b

20−1=20−20+b

19=0+b

19=b

We can substitute for m and b in the formula to find the equation:

y=−5x+19

User Loupax
by
3.4k points