Answer:

Step-by-step explanation:
Given


Required:
Determine the time taken to return to the ground
From the equation given; height (h) is a function of time (t)
When the rocket returns to the ground level, h(t) = 0
Substitute 0 for h(t) in the given equation

becomes

Solve for t in the above equation

Factorize the above expression

Split the expression to 2

Solving the first expression

Divide both sides by -4



Solving the second expression

Add 30 to both sides


Divide both sides by 4



Hence, the values of t are:
and 
shows the time before the launching the rocket
while
shows the time after the rocket returns to the floor
Answer:
x=0.9
Step-by-step explanation:
1.convert to improper fractions
4x+9/7/3=3x/0.5
2.Apply fraction cross multiply
(4x+9) * 0.5=7/3 * 3x
3. simplify
(4x+9) *0.5 =7x
4.Expand
2x+4.5=7x
5.Subtract 4.5 from both sides
2x=7x-4.5
6.Subtract 7x from both sides
2x-7=7x-4.5-7x
7.Simplify
-5x=-4.5
7.Divide by -5
x=0.9
I think it is"A" hope it help
X/3 has to be smaller tha 80%
so x can be 2 since 2/3=66% about
1/2 is less thn 2/3
answer is x is 2
Answer:


Step-by-step explanation:
Let
. We have that
if and only if we can find scalars
such that
. This can be translated to the following equations:
1. 
2.
3. 
Which is a system of 3 equations a 2 variables. We can take two of this equations, find the solutions for
and check if the third equationd is fulfilled.
Case (2,6,6)
Using equations 1 and 2 we get


whose unique solutions are
, but note that for this values, the third equation doesn't hold (3+2 = 5
6). So this vector is not in the generated space of u and v.
Case (-9,-2,5)
Using equations 1 and 2 we get


whose unique solutions are
. Note that in this case, the third equation holds, since 3(3)+2(-2)=5. So this vector is in the generated space of u and v.