Answer:
t = -2.566s and -1.169s
Step-by-step explanation:
Given the height of the ball expressed at
h(t) = 5t²+14t+3
The ball will hit the ground at h(t) = 0
Substitute and get t
0 = 5t²+14t+3
Use general formula
t = -14+/- √14²-4(5)(3)/2(5)
t = -14+/- √196-60)/10
t = -14+/- √136/10
t =-14+/- 11.66/10
t = -25.66/10 and -2.338/2
t = -2.566s and -1.169s
Hence the ball will hit the ground at these times
Answer:
a. 47
b. 87
c. 127
Step-by-step explanation:
Assume a total of 4 exams ( first 3 plus a final)
Let final score be X,
Hence, average score = (85 + 71 + 77 + x) / 4 = (233 + x) / 4
a) to get a C, the average score must be 70
70 = (233 + x) / 4
(233 + x) = 70 (4) = 280
x = 280 - 233 = 47 (Ans)
b) to get a B, the average score must be 80
80 = (233 + x) / 4
(233 + x) = 80 (4) = 320
x = 320 - 233 = 87 (Ans)
c) to get a A, the average score must be 90
90 = (233 + x) / 4
(233 + x) = 90 (4) = 360
x = 360 - 233 = 127 (Ans)
Answer:
Step-by-step explanation:
Straight