PLEASE HELP! NEED ANSWERS FOR A,C,D,E,F
1 answer:
You might be interested in
Answer:
The pebble will hit the ground 8.29 second after it is thrown.
Step-by-step explanation:
Given that,
The height of the pebble after t seconds is given by the equation
h= -16t²+24 t+900.
When the pebble hit the ground, the height of the pebble will be zero.
So putting h=0 in the given equation.
0 = -16t²+24 t+900
⇒-4(4t²-6t-225)=0
⇒4t²-6t-225=0
Applying quadratic formula , here a=4, b= -6 and c= -225.
⇒ t = 8.29, -6.79
Since time can not negative.
∴t=8.29 seconds.
The pebble will hit the ground 8.29 second after it is thrown.
Answer:
d) 87
Step-by-step explanation:
to solve this lets set up the equation
then we multiply 4 on both sides
253+x=340
and subtract 253 on both sides
x=87
to double check take the averages
(87+85+70+98)/4=85