SOLUTION: if x=1 upon 2-√ 3 find value of x3-2x2-7x+5

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Question 761975: if x=1 upon 2-√ 3 find value of x3-2x2-7x+5
Answer by sachi(548) About Me  (Show Source):
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x=1 upon 2-√ 3 =1/(2-√3)=(2+√3)/(2+√3)(2-√3)=(2+√3)/(4-3)=2+√3
so x-2=√3.............1
now x3-2x2-7x+5=x3-2x2-7x+14-14+5=x2(x-2)-7(x-2)-9=x2√3-7√3-9
-(2+√3)^2*√3-7√3-9=(4+3+4√3)√3-7√3-9=(7+4√3)√3-7√3-9=7√3+12-7√3-9=3