Answer:
Formula for circumference;
C = 2πr
replace those values
C = 2 x 3.14 x 9
C = 56.52 inches, C
I assume you are trying to solve for each variable. if thats the case you want to use one equation to solve for y and then plug the y value into the next variable
Problem: y =-3x=4 so -3x+4=3x-2
x=1
plug x value into one of the equations
y=3(1)-2
y=1
Answer:
the answer is 
Step-by-step explanation:

hope this helps :)
Try using Symbolab, I use it all the time it gives the correct answer and it gives good explanations.
Answer:The answer is 63
Step-by-step explanation:
You would divide 126/2 = 63, to check, you would see if there is a 1:1: ratio between number of redheads and all other student!