+0  
 
+3
52
2
avatar+58 

Help me, please

solve by addition or subtraction

 

y=2x+3

+ x+3y=-5

ManuelBautista2019  Sep 25, 2017
Sort: 

2+0 Answers

 #1
avatar+76850 
+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

 

 

 

cool cool cool

CPhill  Sep 25, 2017
 #2
avatar+17 
+2

you are solving by additon wink

maximumride14  Sep 25, 2017

28 Online Users

avatar
avatar
avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details