2 44 55 66 68 67 45 90 23воовтвла
<span>log₄(7-x)=2</span>
<em><u>(х - 5) - (2 - 2х) = 6</u></em>
1 - 1/cos^2a = (cos^2a-1)/cos^2a= -sin^2a/cos^2a= -tg^2a
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