Practice china-kaoyan-math-1 questions with answers and explanations.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
Rewrite the value using base 5: 3125 = 5^5. Matching exponents gives x = 5.
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Use the circle-area formula A = πr². Substituting r = 9 gives A = π × 9² = 81π.
By Vieta’s formula, the sum of the roots equals the coefficient 13.
aₙ=a₁+(n−1)d=7+(16−1)×6=97.
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The sum is n(n+1)/2=21, so the mean is 21/6.
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There are 5 favourable outcomes out of 13 equally likely outcomes, so P(red)=5/13.
The coordinate differences are 3 and 4, so the distance is √(3²+4²)=5.
f′(x)=12x²+8x. Substituting x=4 gives 224.
An antiderivative is 4/2 x²+4x. At x=5, the value is 70.0.
The dot product is 4×4+5×6=46.
Percentage=(7/42)×100=16.67.
