Question

Solve it♥️☝️☝️

CLASS 9TH....☝️☝️​

Answer 1

Step-by-step explanation:

hope it helps uu...

formule used:

(a+b)3 = a3+b3+3a2b+3ab2

(a+b)2 = a2+b2+2ab

Answer 2

Solution:

Given:

• $\sf x=\dfrac{\sqrt{3}+1}{2}$

To Find:

• Value of 4x³ + 2x² - 8x + 7

Now, put the value of x in given equation,

$\implies \sf 4x^{3}+2x^{2}-8x+7\\ \\ \\ \implies \sf 4\Bigg[\dfrac{\sqrt{3}-1}{2}\Bigg]^{3}+2\Bigg[\dfrac{\sqrt{3}+1}{2}\Bigg]^{2}-8\Bigg[\dfrac{\sqrt{3}+1}{2}\Bigg]+7\\ \\ \\ \implies \sf 4\Bigg(\dfrac{3\sqrt{3}+1+3(3)(1)+3(\sqrt{3})(1)}{8}\Bigg)+2\Bigg(\dfrac{3+1+2\sqrt{2}}{4}\Bigg)-8\Bigg(\dfrac{\sqrt{3}+1}{2}\Bigg)+7\\ \\ \\ \implies \sf 4\Bigg(\dfrac{10+6\sqrt{3}}{8}\Bigg)+2\Bigg(\dfrac{4+2\sqrt{3}}{4}\Bigg)-8\Bigg(\dfrac{\sqrt{3}+1}{2}\Bigg)+7$

$\implies \sf 5+3\sqrt{3}+2+\sqrt{3} -4\sqrt{3}-4+7\\ \\ \\ \implies \sf 10$

Hence, Answer is 10.