30 cups is the correct answer
Set up a system of equations:
x + y = 9
1/x +1/y = 1/2
The easiest way to solve would be substitution.
x + y = 9 can be solved for y:
y = 9 - x
Then plug this into the second equation and solve for x:
1/x + 1/(9-x) = 1/2
(9-x) + x = x(9-x)/2
9 = (9x-x²)2
18 = 9x - x²
x² - 9x + 18 = 0
(x-6)(x-3) = 0
x = 6, 3
You can check your answer by plugging the two numbers back into both of the equations:
6 + 3 = 9
1/6 + 1/3 = 1/2
The two numbers are 6 and 3.
It should be -48. Multiply 40 by the reciprocal and simplify.
180/60 = the number of student for 1%
180/60 = 3
so 1% of the school's population is 3 students
so, 3 x 100 = 300 students
and to check:
300 x .60 = 180
so, the total population of the school is 300
Answer:
Step-by-step explanation:
This question is asking us to find where sin(2x + 30) has a sin of 1. If you look at the unit circle, 90 degrees has a sin of 1. Mathematically, it will be solved like this (begin by taking the inverse sin of both sides):
![sin^{-1}[sin(2x+30)]=sin^{-1}(1)](https://tex.z-dn.net/?f=sin%5E%7B-1%7D%5Bsin%282x%2B30%29%5D%3Dsin%5E%7B-1%7D%281%29)
On the left, the inverse sin "undoes" or cancels the sin, leaving us with
2x + 30 = sin⁻¹(1)
The right side is asking us what angle has a sin of 1, which is 90. Sub that into the right side:
2x + 30 = 90 and
2x = 60 so
x = 30
You're welcome!
