Question

Which statement justifies that x2 + 3x - 1 multiplied by 2x2 - 2x + 1 obeys the closure property of multiplication?

The result 2x4 - 6x2 - 1 has a degree of 4.

The result 2x4 - 6x2 - 1 is a trinomial.

The result 2x4 + 4x3 - 7x2 + 5x - 1 has a degree of 4.

The result 2x4 + 4x3 - 7x2 + 5x - 1 is a polynomial.

Answer 1

@Abhisar @LoveYou* @vksmith7

Answer 2

umm I'm not sure

Answer 3

I didn't get any of those as my answers

Answer 4

one sec

Answer 5

its c or d

Answer 6

I know not very helpful

Answer 7

No thats great. Thanks

Answer 8

'closure property of multiplication' means that if you have one set and type of numbers and multiply them you get the same type of numbers.

The answer is D. You start with 2 polynomials, multiply them and the result is also a polynomial. C is not the correct answer, because that takes the perspective of degree in exponents. The first two sets aren't 4th degree, they're both 2nd degree. If you multiply two 2nd degree sums with each other, out comes a 4th degree, not a new 2nd degree. If the degree characteristic was a closure property when multiplying you'd have to have the same degree coming out as what you put in.

So the sole right answer is D.