The slope of the line passing through the points (−5,1) and (x,−4) is −5/8. Find x.
- A4
- B3
- C2
- D-1
Solution & Step-by-step Explanation
The formula for the slope m of a line passing through (x
1
,y
1
) and (x
2
,y
2
) is:
m=
x
2
−x
1
y
2
−y
1
Given:
(x
1
,y
1
)=(−5,1)
(x
2
,y
2
)=(x,−4)
m=−
8
5
Substitute the values:
−
8
5
=
x−(−5)
−4−1
−
8
5
=
x+5
−5
Dividing both sides by −5:
8
1
=
x+5
1
x+5=8
x=3
1
,y
1
) and (x
2
,y
2
) is:
m=
x
2
−x
1
y
2
−y
1
Given:
(x
1
,y
1
)=(−5,1)
(x
2
,y
2
)=(x,−4)
m=−
8
5
Substitute the values:
−
8
5
=
x−(−5)
−4−1
−
8
5
=
x+5
−5
Dividing both sides by −5:
8
1
=
x+5
1
x+5=8
x=3