Help me, please

solve by addition or subtraction

y=2x+3

+ x+3y=-5

ManuelBautista2019
Sep 25, 2017

#1**+2 **

y = 2x +3 subtract 2x from both sides ⇒ -2x + y = 3

1x+3y= -5

The idea is to focus on eliminating a variable......I see that by multiplying the second equation by 2 we can add it to the first equation and eliminate x

So........we have

-2x + y = 3

2x + 6y = -10

___________

7y = - 7 divide both sides by 7

y = -1

Sub this into any equation to find x

y = 2x + 3

-1 = 2x + 3 subtract 3 from both sides

-4 = 2x divide both sides by 2

x = -2

CPhill
Sep 25, 2017