The slope of line l is twice its y-intercept, what is the x-intercept

Question

The slope of line  l  is twice its  y -intercept, what is the  x -intercept of line  l ?
A)  \frac{1}{4} 
B)  \frac{1}{2} 
C) - \frac{1}{3} 
D) - \frac{1}{2} 
E) - \frac{1}{4}

gmatway · Answer

Let the line L eq be y = mx +c , we are told m= 2c (y intercept is = c , y intercept means point where x = 0 ) 
 so now we have y = 2c x + c . to find x intercept put y=0 
0 =2c x + c
-c/2c = x => -1/2 = x intercept . option D

GMATinsight · Answer

Observations
1) The sign of both x and Y intercepts must be same i.e. Slope must be Negative (both +ve Intercepts) or (both -ve Intercepts)
2) Slope (absolute value) = y-intercept/x-intercept = a/2a = 1/2

i.e Slope of line l will be   -\frac{1}{2}

Answer: Option D

MathRevolution · Answer

y = mx + c

Put x = 0 for y intercept . Therefore y = m(0) + c => y = c.

Now, Line L has equation as y = mx + c and given m = 2c

For x- intercept put y = 0.

=> 0 = 2cx + c

=> - c = 2cx

=> x =  \frac{-1}{2}

Answer D

Kinshook · Answer

Asked: The slope of line  l  is twice its  y -intercept, what is the  x -intercept of line  l ?

y = 2mx + m

For x-intercept, put y=0
0 = 2mx + m
x = - 1/2

IMO D

Abhineetegi · Answer

Equation of line : y=mx+c where c is y intercept and m = slope
m = 2c (given)
=> y=(2c)x+c
for x-intercept, y=0
=> 0 = (2c)x+c
=> x = -c/2c => x=-1/2

IMO OA is D.

Loser94 · Answer

Let the line be y = mx +c , and we know m= 2c ( y intercept).
So x intercept will be when y=0, 0=2c*x+c
x=-1/2
Answer D

firas92 · Answer

We can also assume values.

Let y intercept be 2 and slope be 4.

So the equation of the line must be y=4x+2

Now set y=0 to find the x intercept

0=4x+2 or x=-1/2

Answer is (D)

My GMAT Debrief  !

AjitJangale · Answer

Given:

Slope of Line is 2 times y intercept.

Equation of line y=mx+c

m=2c

y=2cx+c

To find x intercEpt put y=0

0=2cx+c

2cx=-c

x=-c/2c

x=-1/2.

IMO Ans is D.

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The slope of line l is twice its y-intercept, what is the x-intercept

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The slope of line l is twice its y-intercept, what is the x-intercept

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