Question #f65fd

1 Answer
Mar 1, 2017

k=2k=2

Explanation:

Consider each statement separately.

• ypropx^2larrcolor(blue)" direct variation"yx2 direct variation

• yprop1/zlarrcolor(blue)" inverse variation"y1z inverse variation

Combine the right sides as a product.

• ypropx^2/zlarrcolor(blue)" joint variation"yx2z joint variation

Convert to an equation by introducing k,
color(blue)" the constant of variation" the constant of variation

rArry=kxxx^2/zy=k×x2z

rArry=(kx^2)/zy=kx2z

color(blue)"cross-multiplying" cross-multiplying gives.

kx^2=yzkx2=yz

rArrk=(yz)/x^2k=yzx2

To calculate k, substitute the given values for x, y and z

rArrk=(6xx27)/9^2=162/81=2k=6×2792=16281=2

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