Answer:
45.27feet
Step-by-step explanation:
Given the height of the balloon (in feet) represented by the equation h=−16t2+28.7t+32.4, where t is the time (in seconds) 
Note that the velocity of the balloon at maximum height is zero, hence;
v = dh/dt =0
-32t+28.7 = 0
-32t = -28.7
t = 28.7/32
t = 0.897secs
Get the maximum height
Recall that h=−16t²+28.7t+32.4
h = -16(0.897)²+28.7(0.897)+32.4
h= -12.87+25.74+32.4
h = 45.27feet
Hence the maximum height reached is 45.27feet
 
        
             
        
        
        
PQ // BC 
then
Angle P = Angle B, A is common angle the two triangles are similar
AP/AB  = AQ/AC
8/18 = 12/ AC
AC = 12 * 18/8 = 27 (your ans: D)
AQ + QC = AC
QC = AC - AQ = 27 - 12 = 15 (if it was required) 
tan60 = y/8
y = s tan60 = 8sqrt(3)  (B)
Next time, post each question separately. 
        
             
        
        
        
Answer:
1/10
Step-by-step explanation:
-2/5 + 1/2
-4/10 + 5/10
-4 + 5/10
= 1/10
Hope this helps! 
 
        
                    
             
        
        
        
Answer:
Just use long subtraction by expanding the decimal places of the whole number. This is done by adding a point, and enough zeros to it to match the number of decimal digits in the other number (digits after the decimal point). 
 12345678 
i.e: 5 - 2.48374827, 2.48374827 has 8 decimal digits, so add 8 zeros after the point.
= 
 1 1 1 1 1 1 1 
 5.00000000
 -
 2.48374827
_______________
 2.51625173
7 + 3 = <u>1</u>0, 7 + 2 + <u>1</u> = <u>1</u>0, 8 + 1 + <u>1</u>= <u>1</u>0, 5 + 4 + <u>1</u> = <u>1</u>0, 2 + 7 + <u>1</u> = <u>1</u>0, 3 + 6 + <u>1</u> = <u>1</u>0, 1 + 8 + <u>1</u> = <u>1</u>0, 5 + 4 + <u>1</u> = <u>1</u>0, 2 + 2 + <u>1</u> = <u>5</u><u> </u><u>:</u><u> </u>5.00000000
This is basically borrowing a group of 10s which are the same as 1s in the next decimal place up.
For each digit except the first to the right, let 10 subtract that number from it and minus 1 since the 1 is carried over.
 
        
             
        
        
        
1/2 it's a fifty fifty unless the guys are complete idiots