Ihad 28 tests to mark and finished 54%. how many do i have left

52 tests because you would multiply 28 by 100 then divide by 54. You would get 51.851, but you cannot have and 8th of a test, so you would round up

true statements:

a) x + y = y + x   ⇒ commutative property of addition

b) (x * y) * z = x * (y * z) ⇒ associative property of multiplication

d) (x + y) + z = x + (y + z) ⇒ associative property of addition

false statements:

c) x - y = y - x   should be: x - y = - y + x

e) (x - y) - z = x - (y - z) should be: (x - y) - z = x - (y + z)

step-by-step explanation:

answer

point o.

step-by-step explanation: