A straight line has a slope of 1/2 and a y-intercept of

Expert replies

Previous Topic Next Topic

VJesus12: Legendary Member; Posts: 2276; Joined: Sat Oct 14, 2017 6:10 amFollowed by: 3 members

by VJesus12 » Tue Jun 05, 2018 1:45 am

Timer

00:00

Your answer

Difficulty–

right wrong

Pick an answer to see how members did

A straight line has a slope of 1/2 and a y-intercept of -2. On this line, what is the x-coordinate of the point whose y-coordinate is 10?

1. (8)
2. (12)
3. (13)
4. (16)
5. (24)

The OA is the option E.

How can I find the x-coordinate? Could anyone tell me how to find the equation of the line? Thanks for your help.

Source: Beat The GMAT — Problem Solving | Tue Jun 05, 2018 1:45 am

GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16206; Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members; Location: Vancouver, BC; Thanked: 5254 times; GMAT Score:770

by Brent@GMATPrepNow » Tue Jun 05, 2018 7:13 am

VJesus12 wrote:A straight line has a slope of 1/2 and a y-intercept of -2. On this line, what is the x-coordinate of the point whose y-coordinate is 10?

A. (8)
B. (12)
C. (13)
D. (16)
E. (24)

Given this information, we can write the equation for the line in slope y-intercept form, y = mx + b, where m = the slope and b = the y-intercept

We're told that the slope is 1/2 and the y-intercept is -2
So, the equation of the line is: y = (1/2)x + (-2)
Simplify to get: y = (1/2)x - 2

What is the x-coordinate of the point whose y-coordinate is 10?
In other words, what does x equal when y = 10?
Take the equation of the line, y = (1/2)x - 2 and replace y with 10 to get: 10 = (1/2)x - 2 [now solve for x]
Add 2 to both sides: 12 = (1/2)x
Solve, x = 24

So, when y = 10, x = 24

Answer: E

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com

GMAT/MBA Expert

Scott@TargetTestPrep: GMAT Instructor; Posts: 8246; Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members; Location: Los Angeles, CA; Thanked: 43 times

by Scott@TargetTestPrep » Wed Jun 06, 2018 3:59 pm

VJesus12 wrote:A straight line has a slope of 1/2 and a y-intercept of -2. On this line, what is the x-coordinate of the point whose y-coordinate is 10?

1. (8)
2. (12)
3. (13)
4. (16)
5. (24)

We use the slope-intercept formula for a line: y = mx + b, where m = the slope of the line and b = the y-intercept of the line. Therefore, the equation of the line is:

y = (1/2)x - 2

So, if y = 10, then:

10 = x/2 - 2

12 = x/2

24 = x

Answer: E

Scott Woodbury-Stewart
Founder and CEO
[email protected]

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

Featured schoolRound 2 closes Jan 7, 2027 53 days left

Chicago Booth

Since 1982, 10 Booth faculty members have received the Nobel Prize in Economic Sciences, more than any other business school.

#3
U.S. News rank: $175,000
Median base salary: 670
Average GMAT Focus: 635
Students in the class

Apply to Booth Visit chicagobooth.edu See the full profile

Photo: Warren LeMay, CC BY-SA 2.0

GMAT Course Reviews

563 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (563 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review