If y varies directly as x and inversely as the square of z and if y=20y=20  when x=50x=50 and z=5z=5 how do you find y when x=3x=3 and z=6z=6?  

1 Answer
May 9, 2018

y=5/6y=56

Explanation:

"the initial statement is "ypropx/z^2the initial statement is yxz2

"to convert to an equation multiply by k the constant"to convert to an equation multiply by k the constant
"of variation"of variation

rArry=kxx x/z^2=(kx)/z^2y=k×xz2=kxz2

"to find k use the given condition"to find k use the given condition

y=20" when "x=50" and "z=5y=20 when x=50 and z=5

y=(kx)/z^2rArrk=(yz^2)/x=(20xx25)/50=10y=kxz2k=yz2x=20×2550=10

"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=(10x)/z^2)color(white)(2/2)|))

"when "x=3" and "z=6" then"

y=(10xx3)/36=30/36=5/6