Answer:
0.14 s
Step-by-step explanation:
s = -2.7 t² + 40t + 6.5
Let s = 12
12 = -2.7t² + 40t + 6.5 Subtract 12 from each side
-2.7t² + 40t + 6.5 - 12 = 0
-2.7t² + 40t - 5.5 = 0
Apply the <em>quadratic formula
</em>
a = -2.7; b = 40; c = -5.5
x = 7.41 ± 7.27
x₁ = 0.14; x₂ = 14.68
The graph below shows the roots at x₁ = 0.134 and x₂ = 14.68.
The Moon’s surface is at -12 ft. The ball will be 12 ft above the Moon’s surface (crossing the x-axis) in 0.14 s.
The second root gives the time the ball will be 12 ft above the Moon’s surface on its way back down.
Answer:
Joint variation says that:
if 
and 
then the equation is in the form of:
, where, k is the constant of variation.
As per the statement:
If x varies jointly as y and z
then by definition we have;
......[1]
Solve for k;
when x = 8 , y=4 and z=9
then
Substitute these in [1] we have;
⇒
Divide both sides by 36 we have;
Simplify:
⇒
to find z when x = 16 and y = 6
Substitute these value we have;
⇒
Multiply both sides by 9 we have;
Divide both sides by 12 we have;
12 = z
or
z = 12
Therefore, the value of z is, 12
Well it sounds like you would have to multiply by 2, which is the amount of roofers, then subtract 12.
10 x 2 = 20
20 - 12 = 8
Hope this helped.
Answer:7.5
Step-by-step explanation:
you divided 15 into 2
