Quandaries and Queries


Who is asking: Student
Level: Secondary

If the graphs of y=x and y=2x are drawn on the same set of axes, they will intersect when x is equal to what?

(4)They won't intersect.

I know the answer is number 4 by graphing which is permitted; however, I would like to know if there is any algebraic way to do this type of problem.If yes, please show me how.Thanks.




There really isn't an algebraic way to solve this problem. Your solution by graphing is good. I would have tried the possibilities listed since it is a multiple choice problem

(1) x=1: y = 1, y = 21=2. Not a solution
(2) x=2: y = 2, y = 22=4. Not a solution.
(3) x = 0: y = 0, y =20=1. Not a solution.

Since it is a multiple choice question the answer must be (4).



Go to Math Central