+0  
 
+1
134
1
avatar+32 

simultaneous equations

5x+2y=-2

3x-5y=17.4

yahya  May 13, 2017

Best Answer 

 #1
avatar+5552 
+4

For this we can use the elimination method.

5x + 2y = -2

3x – 5y = 17.4

 

Multiply the top equation through by \(\frac52\) .

\(\frac{25}{2} \) – 5y = -2

 

Now line this up with the second equation and add straight down.

    \(\frac{25}{2} \)x    +    5y = -5

+   3x      –    5y = 17.4

     15.5x +    0y = 12.4

 

15.5x = 12.4

x = 12.4/15.5

x = 0.8

 

Now just use this value for x in either equation to find y.

5(0.8) + 2y = -2

4 + 2y = -2

2y = -6

y = -3

hectictar  May 13, 2017
Sort: 

1+0 Answers

 #1
avatar+5552 
+4
Best Answer

For this we can use the elimination method.

5x + 2y = -2

3x – 5y = 17.4

 

Multiply the top equation through by \(\frac52\) .

\(\frac{25}{2} \) – 5y = -2

 

Now line this up with the second equation and add straight down.

    \(\frac{25}{2} \)x    +    5y = -5

+   3x      –    5y = 17.4

     15.5x +    0y = 12.4

 

15.5x = 12.4

x = 12.4/15.5

x = 0.8

 

Now just use this value for x in either equation to find y.

5(0.8) + 2y = -2

4 + 2y = -2

2y = -6

y = -3

hectictar  May 13, 2017

30 Online Users

avatar
avatar
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