If y varies directly as x and inversely as the square of z and y=1/6 when x=20 and z =6, how do you find y when x = 14 and z=5?

1 Answer
Mar 11, 2018

y=21/125y=21125

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=kxxx/z^2=(kx)/z^2y=k×xz2=kxz2

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

y=1/6" when "x=20" and "z=6y=16 when x=20 and z=6

y=(kx)/z^2rArrk=(yz^2)/x=(1/6xx36)/20=3/10y=kxz2k=yz2x=16×3620=310

"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=(3x)/(10z^2))color(white)(2/2)|)))

"when "x=14" and "z=5" then"

y=(3xx14)/(10xx25)=21/125