You need to go from slope-intercept (

) to standard form (

).
slope-intercept form of your provided values:
now, solve for x and y
Your answer is 
.
Answer:
Given:
and
.
Prove: 
Since
, By the definition of perpendicular lines angles 1, 2, 3 and 4 are 90 degree. similarly
, it means angles 5, 6, 7 and 8 are 90 degree.
We can say that,
,
,
and 
From figure it is noticed that the angle 1 and 5 are corresponding angles.
If two parallel lines are intersected by a transversal, then the corresponding angles are equal.
Since corresponding angles are congruent, therefore the line must be parallel to each other.
Hence proved that
.
Given:
The radius, r=4x
The height,

To find the volume of the cone:
The volume of the cone formula is,

Substitute the values of r and h in the above formula we get,

Hence, the volume of the cone is

Thus, the correct option is option D.
M = 135/19 and n = -5/19
You have to give them like terms so that when you eliminate they cancel out and you can solve. The easiest way to do so is by multiplying the top equation by -4 and the bottom by 3.