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

 Jul 11, 2019
edited by Guest  Jul 11, 2019
 #1
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-2x + y =   k            0.5x + y  = 14

 

These intersect when  x  = -8.4

 

So...this means that

 

0.5 (-8.4) + y  = 14    simplify

 

-4.2 + y  =  14      add 4.2 to both sides

 

y  =  14 + 4.2   = 18.2

 

So....the intersection point  is (-8.4, 18.2)

 

And we have that

 

-2(-8.4)  + 18.2  =  k

 

16.8 + 18.2  = k

 

35  = k

 

Here is the graph : https://www.desmos.com/calculator/xryjrho9rx

 

 

cool cool cool

 Jul 12, 2019

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