Answer:
k=20
Step-by-step explanation:
when x approaches 4, the denominator x-4 approaches 0
if the denominator is 0, it means that this is invalid
if the function is a number over 0 when x=4, it represents a vertical asymptote, which means no limit
so the only way possible to let there be a limit is to let the function be 0/0 when we plug in x=4
so x^2 + x - k = 0 when x = 4
4^2 + 4 - k = 0 ==> 20 - k = 0 ==> k = 20
Answer:
30 s
Step-by-step explanation:
When the ball hits the ground h=0. To find the time t when this happens we must solve the equation h=0.
●h= 0
● -12t^2+360t =0
● t(-12t +360) = 0
● t = 0 or -12t +360 =0
● t=0 or -12t = -360
● t=0 or 12t =360
● t=0 or t=360/12
● t=0 or t= 30
The equation has two solutions.
The ball was fired with an initial speed of 800 feet per second so it cannot hit the ground at t=0.
So the ball hits the ground after 30 s.
Answer:
200
Step-by-step explanation:
The proportion equal to a/b = c/d is A.) A/C = B/D
We will know if a proportion is equivalent when its cross products are equal.
a/b = c/d where ad = bc
since ad = bc, a/c = b/d