SOLUTION: Hello out there,I don't know if I'm in the wrong area or not but I need some help with some variation problems,the first one is,Assume that y varies inversely as x,and y=18 when x=

Question 77145: Hello out there,I don't know if I'm in the wrong area or not but I need some help with some variation problems,the first one is,Assume that y varies inversely as x,and y=18 when x=3.Find the constant of variation.The next one is,Assume that y varies inversely as x.If y=8 when x=2.5,find x when y=2.The next one is,Is it true that 1-y=2x is a direct variation,or is it false.And the last one is,well this one is really confusing,it's something about domain problems,A teacher wises to schedule a quiz or exam during part of a two-hour class.The equation L+E=120 can be used to find the available lecture time "L" given that "E" minutes are planned for the quiz or exam.Determine the ordered pairs that satisfy the equation if the domain is {20,30,45,60}.Thank you for whoever can assit me.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Assume that y varies inversely as x,and y=18 when x=3.Find the constant of variation.
y=k/x
18=k/3
k= 54
------------
Assume that y varies inversely as x.If y=8 when x=2.5,find x when y=2.
y=k/x
8=k/2.5
k=20
EQUATION:
y=k/x
2=20/x
x=20/2=10
----------
Is it true that 1-y=2x is a direct variation,or is it false.
Solve for y:
y=1-2x
Not a direct variation.
------------
A teacher wises to schedule a quiz or exam during part of a two-hour class.The equation L+E=120 can be used to find the available lecture time "L" given that "E" minutes are planned for the quiz or exam.Determine the ordered pairs that satisfy the equation if the domain is {20,30,45,60}.
If L=20, E=100
If L=30, L=90
If L=45, L=75
If L=60, L=60
---------------
Cheers,
Stan H.
RELATED QUESTIONS
Hello out there,I need some help with some problems,the first one is Find the excluded... (answered by jim_thompson5910)

Hello out there,I need some help with some factoring problems,the first one is,Solve by... (answered by praseenakos@yahoo.com)

Hello out there,I need some help with some math problems,the first one... (answered by scianci)

Hello out there,I need some help with some problems,the first one is,Factor... (answered by elima)

I need some help. It simply says find the solutions but I am not sure what method it is... (answered by Theo,mananth)

Hello out there,I'm having some trouble with some problems that I need help with,the... (answered by checkley75)

Hello out there to everyone,I need some help with some problems,the first one... (answered by stanbon)

Hello out there,I need some help with some really tough problems,I only have two of... (answered by solver91311)

Joe Smith in the first half of the baseball season has 33 hits out of 120 times at bat.... (answered by joyofmath,checkley71)