Answer:
r = 9
Step-by-step explanation:
cross multiply
9 * r = 81
9r = 81
divide both sides by 9
r= 81/9
r = 9
x=25,y=15 Not to sure abt this answer but I think I got it
Answer:
Step-by-step explanation:
Given that L is a line parametrized by

The plane perpendicular to the line will have normal as this line and hence direction ratios of normal would be coefficient of t in x,y,z
i.e. (2,3,-1)
So equation of the plane would be of the form

Use the fact that the plane passes through (2,0,-1) and hence this point will satisfy this equation.

So equation is

b) Substitute general point of L in the plane to find the intersecting point

i.e. same point given.
Answer:
-1, 6
Step-by-step explanation:
x + y = 5
xy = -6
Take first equation and rewrite it. y = -x + 5
Then substitute the new equation in the second one.
x(-x + 5) = -6
-x^2 + 5x + 6 = 0
Divide by -1
x^2 - 5x - 6
(x + 1)(x - 6) = 0
x = -1, 6