Solve (7-4-3)(15-6-2)+3×5×2: Order of Operations Challenge

Let's simplify this expression while following the order of operations which states that exponents come before multiplication and division, which come before addition and subtraction, and that parentheses come before all of these,

Therefore, we'll start by simplifying the expressions in parentheses first:
$(7-4-3)(15-6-2)+3\cdot5\cdot2= \\ 0\cdot7+3\cdot5\cdot2=$

We'll continue and perform the multiplications in the two terms we got in the expression in the last stage, this is because multiplication comes before addition. In each term we'll perform the multiplications step by step from left to right, also remember that multiplying any number by 0 gives a result of 0:

$0\cdot7+3\cdot5\cdot2= \\ 0+15\cdot2= \\ 30$

Note that since the commutative property of multiplication applies, and in the second term from the left in the expression we simplified above there is multiplication between all terms, the order of operations in this calculation doesn't matter (it's not necessary to perform the left multiplication first etc. as we did), however it is recommended to practice performing operations from left to right as this is the natural order of arithmetic operations (in the absence of parentheses, or other preceding arithmetic operations according to the known order of operations mentioned at the beginning of this solution)

Therefore the correct answer is answer D.