Which contacts section results from the intersection of the plane and the double nap cone shown in the figure

your choice is correct: hyperbola

Step-by-step explanation:

When the plane intersects both naps of the cone, the result is a hyperbola. When only a single nap is intersected (and the plane is parallel to the edge of the cone), the curve is a parabola. An ellipse or circle results when the plane crosses both edges of the cone on the same nap.

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so: