i cannot solve this for the life of me...i think that it is too late or something...AHHH please help!
80=24t-0.9t^2
2006-11-26 12:15:45 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
3.9 and 22.76
2006-11-26 12:19:36 · answer #1 · answered by aznwangstaaa 2 · 0⤊ 0⤋
Subtract 80 from both sides then multiply everything in the equation by 10 to get rid of the decimal. This will simplify the problem to -9t sqd + 24t -80 = 0. Using the quadratic formula the solution is (-24 plus or minus radical - 2364) / -18. I would use an algebra 1 text or an introductory college algebra text. I was an Algebra instructor for a number of years. Have a great week!!
Eds
2006-11-26 12:29:26 · answer #2 · answered by Eds 7 · 0⤊ 0⤋
Subtract 80 to the other side, so you get 0 = -0.9t^2 + 24t - 80, then factor out a -1, so you get 0 = 0.9t^2 - 24t + 80, then just factor into the (t - number) (t - number) using quadratic formula or trial/error. I think that's how you solve it.
2006-11-26 12:22:35 · answer #3 · answered by on my mind 2 · 0⤊ 0⤋
24t-0.9t^2=80
-0.9t^2 + 24t - 80 = 0.
0.9t^2 -24t + 80 = 0
Just use quadratic formula.
x = (-b ± sqrt(b^2 - 4ac)/2a
a = 0.9, b = -24, c = 80
x = (24 ± sqrt(24^2 - 4*0.9*80)/1.8.
Gahhh, I don't know what that square root is so we need a calculator.
Plugging (24 + sqrt(24^2 - 4*0.9*80))/1.8 into google gives x = 22.7614237
Plugging (24 - sqrt(24^2 - 4*0.9*80))/1.8 into google gives x = 3.90524292
Voila two answers.
2006-11-26 12:22:57 · answer #4 · answered by Edgar Greenberg 5 · 0⤊ 0⤋
22.76 or 3.905 (40 plus or minus 20 times square root of 2 divided by 3.
2006-11-26 12:31:53 · answer #5 · answered by PK 1 · 0⤊ 0⤋
make the equation equal zero and then multiple the equation by -10 and you get
-10(9t^2-240+800=0)
try to factor this to fand the two values for t and there is your answer.
2006-11-26 12:26:11 · answer #6 · answered by lunatic2300 1 · 0⤊ 0⤋