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If x=3+root 5÷2,show that x+1÷x=3 and find x cube+1÷x cube=? |
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Answer» ONG>ANSWER: x+1x=3 (x+1x)3=33 x3+3.x2.1x+3.x.1x2+1x3=27 (x3+1x3)+3.x2.1x+3.x.1x2=27 x3+1x3+(3x+3x)=27 x3+1x3+3(x+1x)=27 x3+1x3+3×3=27 x3+1x3+9=27 x3+1x3=18 Therefore the answer is 18 |
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