Solving Direct, Inverse, and Joint Variation Problems

What is the equation for y if it varies directly with x?

• y = k - x

• y = k + x

• y = kx

• y = k / x

If y varies inversely with x and directly with z, which could be a possible equation?

• y = k * x / z

• y = k / (x * z)

• y = k / x * z

• y = kx + kz

If y varies directly with x and inversely with z, which equation is correct?

• y = k / (x * z)

• y = k * (x + z)

• y = kx / z

• y = kx * z

In a direct variation where y = kx, if x is tripled, how does y change?

• Y is doubled

• Y is tripled

• Y remains the same

• Y is halved

What happens to y in an inverse variation when x is doubled?

• Y is doubled

• Y is halved

• Y remains constant

• Y is quadrupled

For y varying jointly with x and z, if both x and z are doubled, by what factor does y increase?

• 16

• 4

• 2

• 8

How does y change if it varies jointly with x and z, and both x and z are tripled?

• Y is tripled

• Y increases nine times

• Y increases six times

• Y remains the same

If y varies directly with the square of x, what happens to y when x is doubled?

• Y remains the same

• Y is halved

• Y quadruples

• Y doubles

In an inverse variation where y = k / x^3, how does y change if x is tripled?

• Y is multiplied by 27

• Y is divided by 27

• Y is multiplied by 3

• Y is divided by 3

What is the correct equation for y if it varies directly with the cube of x and inversely with the square of z?

• y = k / (x^3 * z^2)

• y = k * (x^3 + z^2)

• y = k * x^2 / z^3

• y = k * x^3 / z^2