Recall that the product (a + b)(a - b) is the
difference of squares, a2 - b2
Examine this same product for radical
expressions. Choose the product of (3+ square root of 7)(3- square root of 7)

Recall that the product a ba b is the difference of squares a2 b2 Examine this same product for radical expressions Choose the product of 3 square root of 73 sq class=

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Answer:

The third option (9+[tex]3\sqrt{7}[/tex]-[tex]3\sqrt{7}[/tex]-[tex]\sqrt{49}[/tex])

Step-by-step explanation:

With FOIL, this can be expanded. (a+b)(a-b) is equal to a²+ab-ab-b² or a²-b².

In this case, all the answers have 4 terms, so we want the first option. This makes the equation 3²+(3×[tex]\sqrt{7}[/tex])-(3×[tex]\sqrt{7}[/tex])-([tex]\sqrt{7}[/tex].

Solving these gives 9+[tex]3\sqrt{7}[/tex]-[tex]3\sqrt{7}[/tex]-7. This is the same as  9+[tex]3\sqrt{7}[/tex]-[tex]3\sqrt{7}[/tex]-[tex]\sqrt{49}[/tex].

**This content involves multiplying with surds and expanding perfect squares, which you may wish to revise. I'm always happy to help!

The equivalent expression is (c) [tex]9 - 3\sqrt 7 + 3\sqrt 7 - \sqrt {49}[/tex]

The difference of squares equation is given as:

[tex](a + b)(a - b) = a^2 -b^2[/tex]

And the radical expression is given as:

[tex] (3+ \sqrt 7)(3- \sqrt7)[/tex]

By comparing the above expression to [tex](a + b)(a - b) = a^2 -b^2[/tex], we have:

[tex]a =3[/tex]

[tex]b = \sqrt 7[/tex]

Substitute these values in [tex](a + b)(a - b) = a^2 -b^2[/tex]

[tex] (3+ \sqrt 7)(3- \sqrt7) = 3^2 - (\sqrt 7)^2[/tex]

This gives

[tex] (3+ \sqrt 7)(3- \sqrt7) = 9 - \sqrt {49}[/tex]

By complete expansion, we have:

[tex] (3+ \sqrt 7)(3- \sqrt7) = 9 - 3\sqrt 7 + 3\sqrt 7 - \sqrt {49}[/tex]

Hence, the equivalent expression is (c)

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