Answer:
The time it takes for the stone to reach the ground is 3.94 s. This answer is correct.
Step-by-step explanation:
I believe there's a mistake in the equation shown, the acceleration (number that multiplies t²) should be negative, since the stone is falling, therefore I'll answer assuming it's -16 instead of 16, otherwise there would be no real solution to the equation.
In order to calculate how long it'll take for the stone to hit the ground we must make f(t) = 0 and find the time "t" that makes the equation valid, so we have:
f(t) = -16t² + 248 = 0
-16t² = -248
t² = -248/(-16) = 15.5
t = sqrt(15.5) = 3.94
3x^2-7x-8
explanation:3x^2+8x-15x-8
=3x^2-7x-8
I'm going to assume you've learn sin, cos, and tan. To find a you must do:

Once you find a, you can use the Pythagorean Theorem to find b:

Or you can do:

You can find these functions on a scientific calculator. Let me now if you need more help.
303-147=156 so there are 156 boys. Hope this helps :)
Answer:
158 & 318
Step-by-step explanation:
8+10=18
18+20=38
38+40=78
78+80=158
5x2=10
10x2=20
20x2=40
40x2=80