dux3000 Posted September 14, 2015 Share Posted September 14, 2015 3x + 2y = 52x + 3y = 8Quantity A: xQuantity B: ySolution: http://www.greenlighttestprep.com/module/gre-algebra-and-equation-solving/video/972I solved this by solving for x and y, which turns out to be the slow way. The solution is a lot faster but I don't think I'd ever come up with it on the test. Does anyone have any similar questions that test the same concept so I can practice? Link to comment Share on other sites More sharing options...
TakeruK Posted September 14, 2015 Share Posted September 14, 2015 The method the video used to solve this question is actually one of the standard ways you would solve a system of 2 equations with 2 unknowns. Especially when you notice the coefficients (numbers in front of) the x and y are similar in value, subtracting (or even adding) the two equations together to form another equation is a good idea. To find more practice questions, just google for systems of 2 equations and 2 unknowns and try the adding/subtracting the equations method on them. You might even find a worksheet that is designed for this method! dux3000 1 Link to comment Share on other sites More sharing options...
dux3000 Posted September 14, 2015 Author Share Posted September 14, 2015 Actually I did use the adding/subtracting method, but I changed the equations to 6x + 4y = 10 and 6x + 9y = 24 and then I subtracted them to get -5y = -14 I never thought about subtracting them before two of the terms were the same, Link to comment Share on other sites More sharing options...
TakeruK Posted September 14, 2015 Share Posted September 14, 2015 Oh okay. Yeah, the key thing to remember is that since you don't need to know what x and y individually are, you just need to know which one is bigger, so you just need a relationship (i.e. an equation) that contains both of them dux3000 1 Link to comment Share on other sites More sharing options...
Brent@GreenlightGRE Posted September 14, 2015 Share Posted September 14, 2015 Does anyone have any similar questions that test the same concept so I can practice? Here's a related question to try: http://www.greenlighttestprep.com/module/gre-algebra-and-equation-solving/video/973 Cheers,Brent - Greenlight Test Prep Link to comment Share on other sites More sharing options...
dux3000 Posted September 14, 2015 Author Share Posted September 14, 2015 Here's a related question to try: http://www.greenlighttestprep.com/module/gre-algebra-and-equation-solving/video/973 Cheers,Brent - Greenlight Test PrepFunny. I came across that same practice question a few minutes after I posted my question. Thanks though! Link to comment Share on other sites More sharing options...
Brent@GreenlightGRE Posted September 14, 2015 Share Posted September 14, 2015 Funny. I came across that same practice question a few minutes after I posted my question. Thanks though!Yeah, in fact it's the practice question that comes immediately after the one you posted :-) Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now