Let's look at an example:
2.24 x 21.6

Do normal multiplication and get
48384   This is not correct, until we put the decimals in. To know how to do this, count the number of decimal spaces from the factors. In 2.24, there are 2, because .24. In 21.6 there are 1 because of .6. This mean three places, so 48384 becomes
48.384
~theLocoCoco
 
        
             
        
        
        
Answer:
a = 195 ; c = 615
Step-by-step explanation:
So, you want to start by forming your equations...
I will use 'c' for children and 'a' for adults for my variables
3a + 30 = c  
(this is because of the info that 30 more tickets than 3 times the amount of children's were sold than adult)
then for equation 2:
3c + 5a = 2820
(this is because of the prices of the tickets and the total money raised)
Then, plug in the equation for c
Your equation should look like:
3(3a + 30) + 5a = 2820
You get:
(9a +90) + 5a = 2820
Then:
14a = 2730
So:
a = 195 adult tickets sold
Plug in a, to find c:
3 (195) + 30 = c
585 + 30 = c
c = 615 children tickets sold
 
        
             
        
        
        
F(g(x)) where you see an 'x' in f(x) put a g:
f(g(x)) = 1/(g-7), now step by step: g - 7 = 6/x+7-7=6/x, and 1/(g-7)=1/(6/x)=x/6!
I let the second one for you. Sorry if you disagree!
        
             
        
        
        
Time taken=distance/speed
778000000000/300000000
=2593.33seconds
=43.22 minutes
        
             
        
        
        
B is the right anwser. Hope i helped thanks