Answer:
15/2
Step-by-step explanation:
3y = -x + 3
y= (-1/3)x + 1
perpendicular: 3
y + 1 = 3(x - 6)
y + 1 = 3x - 18
y = 3x - 19
It looks as if "B" is the right angle so
AC is the hypotenuse
AB and BC are the legs
The x-intercept is when y=0, so we plug that in our equation,

. +12 on both sides to get

. Divide by -8 to get
X^2/(x- 9 = 81/(x - 9)
This is the equation for which you want the solution.
Multiplying both sides of the equation by (x - 9) we get
x^2(x - 9)/(x - 9) = 81(x - 9)/(x - 9)
So the (x - 9) goes out from both the denominator and the numerator and then the simplified equation becomes
x^2 = 81
x ^2 = (9)^2
x = 9
So the value of the unknown variable x comes out to be 9.