The lines -2x + y =k and 0.5x +y = 14 intersect when x= -8.4. What is the value of k?
Looking at the second line, when x = -8.4 then
.5 (-8.4) + y = 14
-4.2 + y = 14
y = 14 + 4.2
y = 18.2
So in the equation for the first line we have
-2(-8.4) + 18.2 = k
16.8 + 18.2 = k
35 = k