Algebra, arithmetic, reasoning.
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Divide both sides by the coefficient 3.
Thus, x = 27 ÷ 3 = 9.
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Since 32 = 2⁵, the exponents must be equal.
Therefore, x = 5.
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Twice the efficiency means twice the daily work rate.
Therefore, A takes half of 18 days, which is 9 days.
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In four days, each works twice.
Completed work is 2/15 + 2/20 = 4/30 + 3/30 = 7/30.
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Total distance is 100 + 140 = 240 meters.
Relative speed is 10 + 14 = 24 m/s, so time = 10 seconds.
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Subtract 5 to get 2x = 12.
Dividing by 2 gives x = 6.
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The logarithm asks what power of 10 gives 1,000.
Since 10³ = 1,000, the answer is 3.
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In 5 days, A completes 5/20 = 1/4 of the job.
Therefore, 3/4 remains.
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Let B's rate be 1 unit and A's 3 units, total 4 units.
A alone takes 8 × 4/3 = 32/3 days.
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Relative speed is 66 km/h = 55/3 m/s.
Length = speed × time = 55/3 × 18 = 330 meters.
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Move variable terms to one side and constants to the other.
Then 3x = 15, so x = 5.
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The logarithmic equation means x = 2⁶.
Thus, x = 64.
