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What are some hard mathematics questions for class 9?
Can you recommend some hard mathematics questions for class 9 students?
Sure, here are a few challenging questions:

1. Solve the equation: 2x^2 + 5x - 3 = 0
2. Evaluate: √6 + √15 - √10
3. If the length of a rectangle is doubled and the width is increased by 10%, what is the new area of the rectangle?
4. If the sum of the first n terms of an arithmetic series is given by Sn = 5n^2 + 10n, what is the first term of the series?