Math III - Variations Practice

y varies jointly as x and z

• y=kx/z
• y=kxz
• y=kz/x
• y=k+x+z

y varies inversely as x

• y=kx
• y=k/x
• y=k+x
• y=k-x

y is directly proportional to x and z

• y=kxz
• y=k/xz
• y=k+xz
• y=xz/k

y varies inversely as x and directly as z

• y=kz/x
• y=kx/z
• y=x/kz
• y=z/kx

w varies inversely with y and jointly as a and c

• w=(kac)/y
• w=y/(kac)
• y=w/(kac)
• w=kyac

m varies inversely with the cube of x

• m=k/x³
• m=x³/k
• m=kx³
• m=k-x³

r is inversely proportional to s and directly proportional to the cube of t

• r=kt³/s
• r=ks/t³
• r=k/st³
• r=kt³/s³

The volume, v, of a balloon is directly proportional to the cube of the balloon's radius, r.

• v=kr³
• v=kr
• v=k/r³
• v=k/r

The number, n, of grapefruit that can fit into a box is inversely proportional to the cube of the diameter, d, of each grapefruit.

• n=k/d³
• n=kd³
• d=k/n³
• n=kd

The time, t, that a plane spends on the runway varies inversely as the take-off speed, s

• t=k/s

• t=ks

• t=k-s

• t=s/k