Question

2x + y = 3
x - 2y = -1

If equation one is multiplied by 2 and then the equations are added, the result is _____.

Answer 1

4x+2y=6
+
x-2y=-1

5x=5
x=1

Answer 2

Answer:

If equation one is multiplied by 2 and then the equations are added, the result is x=1.

Step-by-step explanation:

The first equation is given by:

       $2x+y=3$

and the second equation is given by:

        $x-2y=-1---------(2)$

Now on multiplying first equation by 2 we get:

$4x+2y=6---------(1)$

and now on adding this equation to equation (2) we get:

        $4x+2y+(x-2y)=6-1\\\\i.e.\\\\4x+2y+(x-2y)=5$

Now on combining the like terms we get:

$4x+x+2y-2y=5\\\\i.e.\\\\5x=5\\\\i.e.\\\\x=\dfrac{5}{5}\\\\i.e.\\\\x=1$

and on putting the value of x back to the equation (2) we get:

$y=1$