Anonymous
Anonymous asked in Education & ReferenceHomework Help · 9 months ago

# How do you know which variable comes 1st in the answer? Does it matter?

When multiplying a monomial by a polynomial:

2r(3r+7q)

but the worksheet says the answer is 6r^2+14qr

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• wish i was focusing in math class lmao

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• the formal approach is to alphabetize within each term. [I prefer your answer. Easier to see how you obtained it.}

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• Anonymous
9 months ago

It doesn't matter. Do you not remember the "commutative property of multiplication," which says that q times r equals r times q in all cases?

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However, the mathematical convention is to qrite the letter algebraically.

Since 'q' comes before 'r' in the alphabet you would write '14qr'

NB Terms in higher powers come first .

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• Your answer is correct but the worksheet has only put the variables in alphabetical order.

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• alphabetically q is before r

so by convention it is written as 14qr

But note that 14qr = 14rq

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• In algebra qr = rq The worksheet has listed the variables (letters) in the same order as they appear in the English alphabet

Think of Arithmetic: 2 X 3 = 3 X 2

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• Anonymous
9 months ago

Order does not matter, operationally speaking. By means of the commutative axiom, order remains same for multiplication in this way:

a * b = b * a = ab = ba, equals same quantity.

However, arrangement is used for clarity. 2r distributed to 7q is better expressed as 14qr since it is (2r * 7q), hence the q was with 7 before the r.

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