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100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote ## In the coordinate plane, Line A has a slope of -1 and an tagged by: AAPL ##### This topic has 3 expert replies and 0 member replies ### Top Member ## In the coordinate plane, Line A has a slope of -1 and an ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult Veritas Prep In the coordinate plane, Line A has a slope of -1 and an x-intercept of 1. Line B has a slope of 2 and a y-intercept of -2. If the two lines intersect at the point (a,b), what is the sum a+b? A. 0 B. 1 C. 2 D. 3 E. 4 OA B ### GMAT/MBA Expert Elite Legendary Member Joined 23 Jun 2013 Posted: 10197 messages Followed by: 496 members Upvotes: 2867 GMAT Score: 800 Hi All, We're told that in the coordinate plane, Line A has a slope of -1 and an x-intercept of 1 and Line B has a slope of 2 and a y-intercept of -2. The two lines intersect at the point (a,b). We're asked for the sum a and b. When dealing with lines, it often helps to write the given information in 'Slope-Intercept' format (re: Y = (M)(X) + B). Line A has a slope of -1 and an x-intercept of 1.... Y = (-1)(X) + B 0 = (-1)(1) + B 0 = -1 + B 1 = B Thus, Line A is Y = (-1)(X) + 1 Line B has a slope of 2 and a y-intercept of -2 Y = (2)(X) + B -2 = (2)(0) + B -2 = 0 + B -2 = B Thus, Line B is Y = (2)(X) - 2 To find the intercept point, you can either graph the two lines or set the two equations equal to one another (since we know that the 2 lines will intercept at one point)... Y = (-1)(X) + 1 Y = (2)(X) - 2 (-1)(X) + 1 = (2)(X) - 2 3 = 3X 1 = X When X=1, Y=0, so the intercept point is (1,0) and the sum of a and b is 1+0 = 1. Final Answer: B GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 15348 messages Followed by: 1864 members Upvotes: 13060 GMAT Score: 790 AAPL wrote: Veritas Prep In the coordinate plane, Line A has a slope of -1 and an x-intercept of 1. Line B has a slope of 2 and a y-intercept of -2. If the two lines intersect at the point (a,b), what is the sum a+b? A. 0 B. 1 C. 2 D. 3 E. 4 Line A includes points (1, 0) and (a, b) and has a slope of -1. Thus: (b - 0)/(a-1) = -1 b = -a + 1 a+b = 1. The correct answer is B. The information about Line B is irrelevant. _________________ Mitch Hunt Private Tutor for the GMAT and GRE GMATGuruNY@gmail.com If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon. Available for tutoring in NYC and long-distance. For more information, please email me at GMATGuruNY@gmail.com. Student Review #1 Student Review #2 Student Review #3 Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now. ### GMAT/MBA Expert GMAT Instructor Joined 25 Apr 2015 Posted: 2791 messages Followed by: 18 members Upvotes: 43 AAPL wrote: Veritas Prep In the coordinate plane, Line A has a slope of -1 and an x-intercept of 1. Line B has a slope of 2 and a y-intercept of -2. If the two lines intersect at the point (a,b), what is the sum a+b? A. 0 B. 1 C. 2 D. 3 E. 4 OA B We see that an equation of line B is y = 2x - 2. Letâ€™s let the equation of line A be y = -x + k, where k is the y-intercept. Since line A contains the point (1, 0), we have: 0 = -1 + k 1 = k Therefore, an equation of line A is y = -x + 1. Since the two lines intersect, we can find their point of intersection (a, b) by setting their equations equal to each other: 2x - 2 = -x + 1 3x = 3 x = 1 In other words, a = 1. So y = 2x - 2 = 2(1) - 2 = 0 or b = 0. Therefore, a + b = 1 + 0 = 1. Answer: B _________________ Scott Woodbury-Stewart Founder and CEO scott@targettestprep.com See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

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