- ( x² - 2x+ 1) + 4x - 4 + 5 = - x² + 2x - 1 + 4x + 1 = - x² + 6x
<span><em>Решение:
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<u><span>cosa=√(1-cos²a)=√(1-21/25)=√(4/25)=0,4</span></u>
Log2 76,8 - log2 2,4 = log2 (76,8/2,4) = log2 32 = 5
ответ 5
5y-5z+(y-z)²=5(y-z)-(y-z)²=(y-z)(5+y-z)