Answer:
Part a) 
Part b) 
Step-by-step explanation:
Part a) How many gallons of water will be in the pool after 20 minutes?
we know that
Using proportion
Part b) How many gallons of water will be in the pool after 1 hour
we know that
1 hour = 60 minutes
Using proportion
<span>Multiply one of the equations so that both equations share a common complementary coefficient.
In order to solve using the elimination method, you need to have a matching coefficient that will cancel out a variable when you add the equations together. For the 2 equations given, you have a huge number of choices. I'll just mention a few of them.
You can multiply the 1st equation by -2/5 to allow cancelling the a term.
You can multiply the 1st equation by 5/3 to allow cancelling the b term.
You can multiply the 2nd equation by -2.5 to allow cancelling the a term.
You can multiply the 2nd equation by 3/5 to allow cancelling the b term.
You can even multiply both equations.
For instance, multiply the 1st equation by 5 and the second by 3. And in fact, let's do that.
5a + 3b = –9
2a – 5b = –16
5*(5a + 3b = -9) = 25a + 15b = -45
3*(2a - 5b = -16) = 6a - 15b = -48
Then add the equations
25a + 15b = -45
6a - 15b = -48
=
31a = -93
a = -3
And then plug in the discovered value of a into one of the original equations and solve for b.</span>
Factors of 36 are 18,12,9,6,4,3,2,1
The common factor of 16 and 36 are 4,2,1
2×4=8
b×b×b= b^3
so putting them together would be
8×b^3
