Which of the following is the expansion of [tex]\left(3c + d^2\right)^6[/tex]?

A. [tex]729c^6 + 1,458c^5d^2 + 1,215c^4d^4 + 540c^3d^6 + 135c^2d^8 + 18cd^{10} + d^{12}[/tex]

B. [tex]729c^6 + 1,458c^5d + 1,215c^4d^2 + 540c^3d^3 + 135c^2d^4 + 18cd^5 + d^6[/tex]

C. [tex]729c^6 + 1,215c^5d^2 + 810c^4d^4 + 270c^3d^6 + 90c^2d^8 + 15cd^{10} + d^{12}[/tex]

D. [tex]729c^6 + 243c^5d^2 + 81c^4d^4 + 27c^3d^6 + 9c^2d^8 + 3cd^{10} + d^{12}[/tex]

E. [tex]c^6 + 6c^5d^2 + 15c^4d^4 + 20c^3d^6 + 15c^2d^8 + 6cd^{10} + d^{12}[/tex]



Answer :

To find the expansion of [tex]\((3c + d^2)^6\)[/tex], we can use the result from expanding this binomial expression. Let's look at each term from the expansion and compare it to the given options:

The expansion is:
[tex]\[729 c^6 + 1458 c^5 d^2 + 1215 c^4 d^4 + 540 c^3 d^6 + 135 c^2 d^8 + 18 c d^{10} + d^{12}.\][/tex]

Let's compare the given options to this expanded form:

1. [tex]\(729 c^6 + 1458 c^5 d^2 + 1215 c^4 d^4 + 540 c^3 d^6 + 135 c^2 d^8 + 18 c d^{10} + d^{12}\)[/tex]

This option matches our expanded form exactly.

2. [tex]\(729 c^6 + 1458 c^5 d + 1215 c^4 d^2 + 540 c^3 d^3 + 135 c^2 d^4 + 18 c d^5 + d^6\)[/tex]

Here, the powers of [tex]\(d\)[/tex] do not match the expanded expression. Specifically, the terms involving [tex]\(d\)[/tex] have incorrect exponents.

3. [tex]\(729 c^6 + 1215 c^5 d^2 + 810 c^4 d^4 + 270 c^3 d^6 + 90 c^2 d^8 + 15 c d^{10} + d^{12}\)[/tex]

This option does not match because the coefficients [tex]\(1458, 540, 135, 18\)[/tex] are incorrect, particularly for the terms [tex]\(c^5 d^2, c^3 d^6, c^2 d^8, c d^{10}\)[/tex].

4. [tex]\(729 c^6 + 243 c^5 d^2 + 81 c^4 d^4 + 27 c^3 d^6 + 9 c^2 d^8 + 3 c d^{10} + d^{12}\)[/tex]

This option has completely incorrect coefficients for all terms except the first and last powers.

5. [tex]\(c^6 + 6 c^5 d^2 + 15 c^4 d^4 + 20 c^3 d^6 + 15 c^2 d^8 + 6 c d^{10} + d^{12}\)[/tex]

This option does not match at all since the coefficients are not consistent with expanding [tex]\((3c + d^2)^6\)[/tex].

Thus, the correct expansion for [tex]\((3c + d^2)^6\)[/tex] is the first option:
[tex]\[729 c^6 + 1458 c^5 d^2 + 1215 c^4 d^4 + 540 c^3 d^6 + 135 c^2 d^8 + 18 c d^{10} + d^{12}.\][/tex]