9514 1404 393
Answer:
78.71 mph
Step-by-step explanation:
You're looking for the solution to ...
d = 88
0.0015r^2 +r = 88
0.0015r^2 +r -88 = 0
Using the quadratic formula*, we find ...
r = (-1 +√(1² -4(0.0015)(-88)))/(2×0.0015)
r = (-1 +√1.528)/0.003 = 0.236123/0.003 = 78.7077
The speed of the car was about 78.71 mph.
_____
* The quadratic formula will also give a negative answer of about -745 mph, which is not relevant to the situation.
Step-by-step explanation:
4x2+8x−3=0
For this equation: a=4, b=8, c=-3
4x2+8x+−3=0
Step 1: Use quadratic formula with a=4, b=8, c=-3.
x=
−b±√b2−4ac
2a
x= −(8)±√(8)2−4(4)(−3)
2(4)
x= −8±√112
8 x=−1+
1 2 √7 or x=−1+
−1 2 √7
Answer: x=−1+
1 2√7 or x=−1+
−1 2 √7
8:19 means there are 8 bottles of cherry from all 19
<span>When order does not matter you use what is called n choose k formula
n!/(k!(n-k)!) where n is the number of things to choose from and k is the number of choices made, in this case:
20!/(4!(20-4)!)=4845</span>
