We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
267
1
avatar

The lines $-2x + y = k$ and $0.5x + y = 14$ intersect when $x = -8.4$. What is the value of $k$?

 Dec 5, 2017

Best Answer 

 #1
avatar+7354 
+1

The lines  -2x + y = k  and  0.5x + y = 14  intersect when  x = -8.4 .

 

So when  x = -8.4 , both lines have the same  y  value.

Let's plug in  -8.4  for  x  into the second equation to find  y .

 

0.5(-8.4) + y = 14 

-4.2 + y  =  14

y  =  18.2

 

Now we found  x  and  y . Use these values in the first equation to find  k .

 

-2(-8.4) + 18.2  =  k

35  =  k

 Dec 5, 2017
 #1
avatar+7354 
+1
Best Answer

The lines  -2x + y = k  and  0.5x + y = 14  intersect when  x = -8.4 .

 

So when  x = -8.4 , both lines have the same  y  value.

Let's plug in  -8.4  for  x  into the second equation to find  y .

 

0.5(-8.4) + y = 14 

-4.2 + y  =  14

y  =  18.2

 

Now we found  x  and  y . Use these values in the first equation to find  k .

 

-2(-8.4) + 18.2  =  k

35  =  k

hectictar Dec 5, 2017

21 Online Users

avatar