R=4 because 20-4 = 16 and 4 times 4 = 16
Answer:
4 sec
Step-by-step explanation:
let y = 0 which is the height when the rocket hits the ground
-3t^2 + 6t + 24 = 0
-3(t^2 - 2t - 8) = 0
-3(t - 4)(t + 2) = 0
t = 4 or t = -2
time cannot be negative, so t = 4 sec
First lets distribute the 5x
5x^2 + 30x = -50
Lets divide every term by 5
x^2 + 6x = -10
To complete the square we have to half the b value, which in this case is 6. Then square it.
Half of 6 is 3, 3 squared is 9
Add that to both sides of the equation
x^2 + 6x + 9 = -1
Find the binomial squared
(x+3)^2 (If you're wondering how i got that please comment)
(x+3)^2 = -1
Take the square root of the equation of both sides
(x+3) = +/- i
x = -3 +/- i
x = -3 - i
and
x = -3 + i
The probability is 50% or half or 1/2
