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Zorluk: OrtaOperations on Polynomials

The volume of a water tank, in cubic feet, is given by the polynomial V(t)=3t(2t1)(t+4)V(t) = 3t(2t - 1)(t + 4), where tt represents the time in hours since the pump was turned on. When the polynomial is written in standard form, what is the coefficient of the t2t^2 term?

Cevap: 21

Cevap

21
To find the coefficient of the t2t^2 term, we perform polynomial multiplication on the expression V(t)=3t(2t1)(t+4)V(t) = 3t(2t - 1)(t + 4). First, multiplying the binomials (2t1)(t+4)(2t - 1)(t + 4) yields 2t2+7t42t^2 + 7t - 4. Next, distributing the 3t3t term to the trinomial yields 6t3+21t212t6t^3 + 21t^2 - 12t. The coefficient of the t2t^2 term in this standard form polynomial is 21.

Adım Adım Çözüm

1
Expand the product of the two binomials (2t1)(t+4)(2t - 1)(t + 4).
2t2+7t42t^2 + 7t - 4
Use the distributive property (FOIL) to multiply the binomials: 2t(t)+2t(4)1(t)1(4)=2t2+8tt4=2t2+7t42t(t) + 2t(4) - 1(t) - 1(4) = 2t^2 + 8t - t - 4 = 2t^2 + 7t - 4.
2
Multiply the resulting trinomial by the monomial 3t3t.
6t3+21t212t6t^3 + 21t^2 - 12t
Distribute 3t3t to each term: 3t(2t2)+3t(7t)+3t(4)=6t3+21t212t3t(2t^2) + 3t(7t) + 3t(-4) = 6t^3 + 21t^2 - 12t.
3
Identify the coefficient of the t2t^2 term.
21
The coefficient is the numerical factor of the t2t^2 term, which is 21.

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Operations on Polynomials
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