Math CentralQuandaries & Queries


Question from samantha, a student:

the equations of two lines are 6x-y=4 and y=4x +2.what is the value of x in the solution for this system of equations?

Hi Samantha,

First of all let me rewrite the first equation 6x - y = 4. Add y to both sides to get 6x - y + y = 4 + y or 6x = y + 4. Now add -4 to each side to get 6x - 4 = y. Hence the two lines have equations

y = 6x - 4 and
y = 4x + 2.

A solution to this system of equations is a pair of numbers (x, y) that satisfy the equations. Hence if I knew the value x and substituted it into the two equations I would get the same valve each time, y. That is

6x - 4 and 4x + 2 are the same number.


6x - 4 = 4x + 2.

Solve for x.


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS