Р= 20/(20+15) * (20-1)/(20-1+15) = 20/35 * 19/34= 2/7 * 19/17= 38/119
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1) 100⁵/1000²=10¹⁰/10⁶=10⁴=10000
2)3¹⁰*(3³)⁵/(3⁵)⁴ *3=3¹⁰*3¹⁵/3²⁰*3¹=3²⁵/3²¹=3⁴=81
3)(2²)³*(2⁴)²/2¹²=2⁶*2⁸/2¹²=2¹⁴/2¹²=2²=4
4)(3² *5)¹°/5⁸ *3¹⁹=3²° * 5¹°/5⁸ *3¹⁹=3*5²=3*25=75
(сos²a+cos²asina)/(1+sina)=cos²a(1+sina)/(1+sina)=cos²a=(√3/2)²=3/4