Question

If xy=10, what is the value of 2 times x/y times y^2? Please explain your answers.

a) 5
b)8
c)10
d)12
e)20

Answer 1

e) 20... x/y * y^2 = xy. 2xy = 2*10 = 20

Answer 2

x = 10/y,

so
`2 * x/y * y^2`

=
`2 * (10/y)/(y) * y^2`

=
`= 2* 10y^2/y^2`

=
`=2* 10 =20`