What is the solution of the following system -2x-y=1 -4x-2y=-1

Mathematics · High School · Tue Nov 03 2020

Answered on

So we have a system with 2 equations: 1. -2x-y=1 and 2. -4x-2y=-1. 

In order to find the solution, we have to express either X or Y as their own equations and this one to replace it on the other equation given.

In this case: 

 -2x-y=1 ===>  y=-2x-1

The last equation we will replace it on the second equation given from the exercise:

-4x-2y=-1 ===> instead of Y we put -2x-1

-4x-2(-2x-1)=1 ==>-4x+4x+2=1 ==>8x+2=1 ==> 8x=1-2 ==>8x=-1 ==> x=-1/8