Answer: 20 students participate in school sports.
Step-by-step explanation:
Since, Mrs. Perez has 28 students.
And, According to the question, 5 /7 of those students participate in school sports.
Therefore, the students participate in school sports = 5/7 of the total number of the students
= 
= 20
Thus 20 students participate in school sports.
This is college? Woah I'm not advanced. Middle school!
So you do $90 times .40 because 40%=.40 then next you set up your problem
90x.40=36
In total the sales price is $36
So first, you have to get two of the same variables to cancel out. Let's do this for x. In order for the x's to cancel out, we could multiply the bottom problem by 2.
(2) 3x-6y=24
After multiplying all the numbers by 2, you get the equation 6x-12y=48
The set of equations is now
-6x+2y=12
6x-12y=48
Now you can add them. The x variables cancel out, so you are left with the y variable.
2y+-12y=-10y and 12+48=60
Then you would divide 60 by -10 to get y=-6.
You would plug the answer for y into one of the original equations, lets do the top one. -6x+2y=12 becomes -6x+2(-6)=12
You'd multiply the 2 and -6 to get -12 so the equation is
-6x-12=12
The negative 12 turn positive and you add to both sides to get the -6x alone.
-6x-12=12
+12=12
-6x=24
Then divide 24 by -6
X=4
(-4,-6) is your final answer.
Step-by-step explanation:
A= πr^2
r = √(A/π)
r = √(676π/π)
r = 26
C = 2πr
52π
= 163.36