graphsuy

At x = - 8.4

.5(-8.4) + y = 14

y = 14 +4.2 = 18.2

2(-8.4) +18.2 = k = 1 .4

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

The intersection point will also have the same y value

So

-2x + k   =     -0.5x + 14        

-2(-8.4) + k = -.0.5(-8.4) + 14

16.8 + k =  4.2 + 14

16.8 + k =  18.2

k = 18.2 - 16.8   =   1.4