Minnie has a piece of cardboard with length (3x2 − 2x + 1) inches and width (2x2 + 3x − 4) inches. Which statement best explains why the area of the cardboard demonstrates the closure property?
Minnie has a piece of cardboard with length (3x2 − 2x + 1) inches and width (2x2 + 3x − 4) inches. Which statement best explains why the area of the cardboard demonstrates the closure property? It is equal to (6x4 + 9x3 − 12x2 + 8x − 4) square inches, which is also a polynomial like the length and width. It is equal to (6x4 + 5x3 − 16x2 + 11x − 4) square inches, which is also a polynomial like the length and width. The length multiplied by the width is equal to the width multiplied by the length. The length multiplied by the width has the same degree as the width multiplied by the length.
@Michele_Laino
@uri @Preetha
hint: area of a rectangle is given by the subsequent formula: \[{\text{area = base }} \times {\text{ height}}\]
so we can write: \[\Large \begin{gathered} {\text{area = base }} \times {\text{ height = }} \hfill \\ = \left( {3{x^2} - 2x + 1} \right) \times \left( {2{x^2} + 3x - 4} \right) = ...? \hfill \\ \end{gathered} \]
so its gonna be 6x^4-6x^2-4 correct?
I got a different result
uhmm
hint: \[\Large \begin{gathered} \left( {3{x^2} - 2x + 1} \right) \times \left( {2{x^2} + 3x - 4} \right) = \hfill \\ = 6{x^4} + 9{x^3} - 12{x^2} - 4{x^3} - 6{x^2} - 4 = ...? \hfill \\ \end{gathered} \]
how did you get that
I have applied the distributive peroperty of multiplication over addition
ohhh
so now what do i do?
more explanation: \[\large \begin{gathered} \left( {3{x^2} - 2x + 1} \right) \times \left( {2{x^2} + 3x - 4} \right) = \hfill \\ = 3{x^2} \times \left( {2{x^2} + 3x - 4} \right) - 2x \times \left( {2{x^2} + 3x - 4} \right) + 1 \times \left( {2{x^2} + 3x - 4} \right) = ...? \hfill \\ \end{gathered} \]
\[\begin{gathered} \left( {3{x^2} - 2x + 1} \right) \times \left( {2{x^2} + 3x - 4} \right) = \hfill \\ = 3{x^2} \times \left( {2{x^2} + 3x - 4} \right) - 2x \times \left( {2{x^2} + 3x - 4} \right) + 1 \times \left( {2{x^2} + 3x - 4} \right) = ...? \hfill \\ \end{gathered} \]
this is gonna be really drawn out
6x^4+9x3-12x^2-4x^3-6x^2+8x+2x^2+3x-4?
yes! you are right! sorry I have meade an error in my previous result
now you have to simplify similar terms, what do you get?
ohh crap uhmm
can you help me on this i dont really know
oops.. I have made*
grouping similar term, we can write: \[\Large 6{x^4} + {x^3}\left( {9 - 4} \right) + {x^2}\left( { - 12 - 6 + 2} \right) + x\left( {8 + 3} \right) - 4 = ...?\]
\[\large 6{x^4} + {x^3}\left( {9 - 4} \right) + {x^2}\left( { - 12 - 6 + 2} \right) + x\left( {8 + 3} \right) - 4 = ...?\]
uhmm idk
what is 9-4=...?
5
ok! and -12-6+2=...? 8+3=...?
-16 and 11
that's right! So, what is the resulting polynomial?
what you mean
you have to substitute the coefficients which you have fount into this expression: \[6{x^4} + {x^3}\left( {9 - 4} \right) + {x^2}\left( { - 12 - 6 + 2} \right) + x\left( {8 + 3} \right) - 4 = ...?\]
found*
so im still confused? what did we just do with the addition and subtraction?
is the answer C?
the resulting polinomial is: \[\begin{gathered} \left( {3{x^2} - 2x + 1} \right) \times \left( {2{x^2} + 3x - 4} \right) = \hfill \\ \hfill \\ = 3{x^2} \times \left( {2{x^2} + 3x - 4} \right) - 2x \times \left( {2{x^2} + 3x - 4} \right) + 1 \times \left( {2{x^2} + 3x - 4} \right) = \hfill \\ \hfill \\ = 6{x^4} + {x^3}\left( {9 - 4} \right) + {x^2}\left( { - 12 - 6 + 2} \right) + x\left( {8 + 3} \right) - 4 = \hfill \\ \hfill \\ = 6{x^4} + 5{x^3} - 16{x^2} + 11x - 4 \hfill \\ \end{gathered} \]
dang sorry i was confused but thank you so much you were a huge help!!! xD
it is the second option
please wait, I think it is the fourth option, because we got a fourth-degree polynomial, whereas the length and the width are two second-degree polynomials
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