Question

How do you solve the following system?: `8x - 2y = - 4 , -4x + 2y = 2`

Answer 1

`(x,y)to(-1/2,0)`

Explanation:

`8xcolor(red)(-2y)=-4to(1)`

`-4xcolor(red)(+2y)=2to(2)`

`"adding equations "(1)" and "(2)" eliminates the y-term"`

`(1)+(2)" term by term on both sides"`

`(8x-4x)+(-2y+2y)=(-4+2)`

`rArr4x=-2`

`"divide both sides by 2"`

`(cancel(4) x)/cancel(4)=(-2)/4`

`rArrx=-1/2`

`"substitute "x=-1/2" into either of the 2 equations"`

`(2)rArr2+2y=2`

`rArr2y=2-2=0rArry=0`

`"the solution is "(x,y)to(-1/2,0)`