Explanation:
as the other answer said, if is the commutative property of multiplication (the same as for addition, as multiplication is just a shortcut form of special additions) :
a × b = b × a
you need a solution ? you mean, you need this multiplication done and simplified, right ?
you know that
a/b × c/d = (a×c)/(b×d)
so,
-33/57 × -7/28 = -33/57 × -7/(4×7) =
= -33/57 × -1/4 = (-33×-1)/(57×4) =
= 33/228