Question

If x=1/√5-2, find the value of ׳-3²-5x+3

Answer 1

Answer:

$x = \frac{1}{ \sqrt{5} - 2 } \times \frac{\sqrt{5} - 2}{\sqrt{5} - 2} \\ = \frac{\sqrt{5} - 2}{ { (\sqrt{5}) }^{2} - { (2) }^{2} } \\ = \frac{ \sqrt{5} - 2 }{5 - 4} \\ = \sqrt{5} - 2 \\ \blue{\mathfrak{\underline{\large{Finding}}}:} \\ {x}^{3} - 3 {x}^{2} - 5x + 3 \\ = { (\sqrt{5} - 2)}^{3} - 3 {( \sqrt{5} - 2)}^{2} - 5( \sqrt{5} - 2) + 3 \\ = { (\sqrt{5}) }^{3} - {(2)}^{3} - 3 \times {( \sqrt{5} )}^{2} \times 2 + 3 \times \sqrt{5} \times {(2)}^{2} - 3( {( \sqrt{5}) }^{2} - 2 \times \sqrt{5} \times 2 + {(2)}^{2} ) - 5 \sqrt{5} + 10 + 3 \\ = 5 \sqrt{5} - 8 - 30 + 12 \sqrt{5} - 15 + 12 \sqrt{5} + 4 - 5 \sqrt{5} + 13 \\ = 24 \sqrt{5} - 53 + 17 \\ = 24 \sqrt{5} - 36 \\ \\ \red{\mathfrak{\underline{\large{Hope \: It \: Helps \: You }}}} \\ \blue{\mathfrak{\underline{\large{Mark \: Me \: Brainliest}}}}$