Question

If x = 3-v2, then find the value of 3x² + 2x -4.​

Answer 1

Answer:

$3 {x}^{2} + 2x - 4 \\ = 3(3 - \sqrt{2} )^{2} + 2(3 - \sqrt{2} ) - 4 \\ = 3(9 + 2 - 6 \sqrt{2} ) + 6 - 2 \sqrt{2} - 4 \\ = 3(11 - 6 \sqrt{2} ) + 2 - 2 \sqrt{2} \\ = 33 - 18 \sqrt{2} + 2 - 2 \sqrt{2} \\ = 35 - 20 \sqrt{2}$