you mean 3x(4-8y)=3(2xy-5x)?
As one equation is already solved for a variable, in this case y, A is the correct demonstration of substitution
draw a perpendicular line from the directrix passing through the focus, this will be the line of symmetry.
The vertex(h, k) will be located on the line half way between the focus and directrix.
The distance from the focus to the vertex is called the focal length, call it a. The then equation is
(x - h)^2 = 4a(y - k)
the equation can be manipulated to
y = 1/4a(x - h)^2 + k
hope it helps
Answer:
145
Step-by-step explanation:
360-180-35=145