Which of the following are factors of $33yw$33yw? Select all that apply.

$11$11

$66wy$66wy

$yw$yw

$3w$3w

$yw^2$yw2

$33$33

What is the highest common factor of $3$3 and $15x$15x?

What is the highest common factor of $6x$6x and $21$21?

What term must go in the space to complete the statement?

Generalise the properties of operations with fractional numbers and integers.