Set h to 640 and solve for t:
640 = -490t^2 + 1120t
Subtract 640 from both sides:
-490t^2 + 1120t - 640 = 0
The formula to solve a quadratic equation is:
x = -b -/+ sqrtroot (b^2-4ac)/(2a) where a = -490, b = 1120 and c = -640
Solve:
x = -1120 -/+ sqrtroot (1120^2-4(-490)(-640) )/ 2(-490)
x = 8/7 = 1.1428 = 1.14
Time was 1.14 seconds
<span>a=7b+8c+9d-10
a = 8c + 16d - 10
solve for c then
8c = a - 16d + 10
c = (</span>a - 16d + 10) / 8
or
c = a/8 - 2d + 5/4
Answer:
1. 54ft squared 2. 48 cm squared
Step-by-step explanation:
Answer:
in *42* days it will be 45 seconds behind
Step-by-step explanation:
it is already 3 behind and if its only 1 second everyday then you add 1 day until you get to 45 which 42+3 is 45 so the correct answer is 42 days.
