How long does it take for the ball to hit the ground at -5t^2 + 10t + 320

if t is time, then we are solving for the value of t that makes the expression equals 0 (height of the ground)

0=-5t^2+10t+320

factor out -5

0=-5(t^2-2t-64)

use quadratic formula

for at^2+bt+c=0

in our case, a=1, b=-2, c=-64

since and we can't have negative time,

which is about 9.062 seconds

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)

answer: i'm not going to give you the answer, but some hints to work it out.

step-by-step explanation: so, if there is a straight line that means that the line angle is 180°. so we subtract the 2 angle measures provided, (15 and 38) from 180. so the answer is 180 - (38 + 15). (you have to solve the equation)