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### Grade 8 - Mathematics7.45 Problems - IX

 Example: If x+1/x = 3, find the value of x3+1/x3. Solution: Given that, x+1/x = 3 Cubing on both sides, we get (x+1/x)3 = 33 x3+1/x3+3.x.1/x.(x+1/x) = 27 x3+1/x3+3.3 = 27 x3+1/x3+9 = 27 x3+1/x3 = 27-9 x3+1/x3 = 18 Directions: Solve the following problems.
 Q 1: If x+1/x = 4, find the value of x3+1/x3.56525458 Q 2: If x+1/x = 5, find the value of x3+1/x3.113117119115 Q 3: If x+1/x = 7, find the value of x3+1/x3.326328324322 Q 4: If x+1/x = 9, find the value of x3+1/x3.708704702706 Q 5: If x+1/x = 8, find the value of x3+1/x3.484486482488 Q 6: If x+1/x = 2, find the value of x3+1/x3.4862 Question 7: This question is available to subscribers only! Question 8: This question is available to subscribers only!

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