SOLUTION: I missed the day that we went over this and my teacher didnt teach it to me well, so im wondering how to figure... The variable z varies jointly with x and y. a)write an equati

Algebra ->  Rational-functions -> SOLUTION: I missed the day that we went over this and my teacher didnt teach it to me well, so im wondering how to figure... The variable z varies jointly with x and y. a)write an equati      Log On


   



Question 32382: I missed the day that we went over this and my teacher didnt teach it to me well, so im wondering how to figure...
The variable z varies jointly with x and y.
a)write an equation relationg z, x, and y.
b) if x=2, y=1/8, z=3 then find z when x=3&y=-4

If you can just give me an explanation of how to figure this out, that'd be great (do i use z=k(xy)?) If you explain some basics on this subject, i should figure it out. Thanks

Answer by venugopalramana(3286) About Me  (Show Source):
You can put this solution on YOUR website!
The variable z varies jointly with x and y.
a)write an equation relationg z, x, and y.
b) if x=2, y=1/8, z=3 then find z when x=3&y=-4
Z VARIES JOINTLY WITH X AND Y MEANS ...
Z=KXY...WHERE K IS A CONSTANT...{Z VARIES AS X OR VARIES DIRECTLY AS X MEANS
Z=KX...WHERE K IS A CONSTANT.
Z VARIES INVERSELY AS X MEANS ....Z=K/X...WHERE K IS A CONSTANT...}
X=2,Y=1/8 AND Z=3...
HENCE...3=K*2*1/8=K/4........OR.....K=3*4=12
SO IF X=3 AND Y= -4 THEN
Z=12*3*(-4)= -144