Question

11th question answer please​

Answer 1

Answer:

B

Step-by-step explanation:

$(3 { + \sqrt{5} )}^{2} (3 - { \sqrt{5}) }^{2} \\ = ({3}^{2} + { \sqrt{5} }^{2} + 2 \times 3 \times \sqrt{5} ) \times \\ ( {3}^{2} + { \sqrt{5} }^{2} - 2 + \times 3 \times \sqrt{5} ) \\ = (9 + 5 + 6 \sqrt{5} )(9 + 5 - 6 \sqrt{5} ) \\ = (14 + 6 \sqrt{5} )(14 - 6 \sqrt{5} ) \\ = 14(14 - 6 \sqrt{5} ) + 6 \sqrt{5} (14 - 6 \sqrt{5} ) \\ = 196 - 84 \sqrt{5} + 84 \sqrt{5 } - 36 \times 5 \\ = 196 - 180 \\ = 16$

Answer 2

Step-by-step explanation:

(3+√5)^2*(3-√5)^2

(9+5+6√5)(9+5-6√5)

(14+6√5)(14-6√5)

(14)^2-(6√5)^2

196-180=16

or

((3+√5)*(3-√5))^2

(3^2-√5^2)^2

(9-5)^2=4^2=16