Question

If x= 1 upon 2+√3 then find the value of , 2x³-7x³-2x+1 ..I want the answer step by step .Thanks.

Answer 1

x = 1/ 2+√3
x = 1/ 2+√3 x 2-√3/2-√3
x = 2 -√3/ 2²- √3²
x = 2-√3/ 4-3
x = 2-√3/1
x = 2-√3
2x³ - 7x³- 2x +1
= -5x³ - 2x + 1
= -5 (2-√3)³-2 x (2-√3) + 1
= -5 [(2)³ -3 x 2² x√3 + 3 x 2 x(√3)² -(√3)³]
= -5 [ 8-3 x 4 x√3+6 x 3- 9] -4 +2√3+1
= -5[8- 12 x√3+ 18 -9 ] -4+2√3 +1
= -5 [-4 x√3+9 ] -4 +2√3+1
= -5 x-4√3+9-4+2√3+1
= -20√3 + 5+ 2√3 + 1
 =  -18√3 + 6