A straight line in the xy-plane has a slope of 2 and a

This topic has expert replies
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Sun Feb 24, 2019 8:31 am
BTGmoderatorLU wrote:Source: GMAT Prep

A straight line in the xy-plane has a slope of 2 and a y-intercept of 2. On this line, what is the x-coordinate of the point whose y-coordinate is 500?

A. 249
B. 498
C. 676
D. 823
E. 1,002

The OA is A
The question conveniently gives us the information to write the equation of the line in slope y-intercept form, y = mx + b, where m = slope and b = the y-intercept.

Line in the xy-plane has a slope of 2 and a y-intercept of 2
So, the equation of the line is: y = 2x + 2

On this line, what is the x-coordinate of the point whose y-coordinate is 500?
To find the corresponding x-value, we'll take the equation y = 2x + 2 and replace y with 500
We get: 500 = 2x + 2
To solve for x, first subtract 2 from both sides to get: 498 = 2x
Solve: x = 498/2 = 249

Answer: A

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image

Legendary Member
Posts: 2499
Joined: Sun Oct 29, 2017 2:04 pm
Followed by:6 members

by swerve » Mon Feb 25, 2019 8:37 am
The slope of 2 and a y-intercept of 2, y-coordinate is 500
$$y = 2x + 2 \\ 498 = 2x \\ x = 249$$