You have 9n and -7 in total so the answer is 9n-7. You add up all the numbers and then add up the numbers with n attached to them
answer: where is the question?
Let,the time taken by larger pipe = x
By smaller pipe = x+5
It would be: 1/x + 1/(x+5) = 9/100
= x+5+x /(x)(x+5) = 9/100
= 2x+5 / x²+5x = 9/100
= 100(2x + 5) = 9(x² + 5x)
= 200x + 500 = 9x² + 45x
= 9x² - 155x - 500 = 0
= 9x² - 180x + 25x - 500 = 0
= 9x(x - 20) + 25(x - 20) = 0
= (9x + 25) (x - 20) = 0
= x = -25/9 or x = 20
Time can't be in negative so -25/9 is rejected.
Now,x + 5 = 20 + 5 = 25
In short, Your Larger pipe takes 20 minutes and smaller pipe takes 25 minutes
Hope this helps!
So since this is half a circle, we have to divide the area of a circle by 2. So that would give us 1/2 pi* r^2. We find the radius by dividing 10 by 2. So the radius is 5. Plugging that in for r in 1/2(pi)(r^2) we get 1/2(pi)(5^2) which is 25pi/2. Turning pi into 3.14 we have (25(3.14))/2 which is 78.5/2 which is approximately 39.25 units^2
