Associative multiplication:
(x*y)*z = x*(y*z)
f (hg) = (fh)g is an example of applying the Associative Property of Multiplication?
From the previous definion we can conclude that the statement is true
5(9*4) + 7 + (3+1)
Using Associative property and commutative property:
1 + (3+7) + 4*(5*9)