(6а-в)²-(9а-в)(4а+2в)=36а²-12ав+в²-(36а²+18ав-4ав-2в²)=36а²-12ав+в²-36а²-18ав+4ав+2в²=-26ав+3в²=3в<span>²-26ав</span>
Решение во вложении
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2sinx*cosx*sinx/cosx=1
2Sin²x=1
sin²=1/2
sinx=-1√2⇒x=-π/4+2πk U x=-5π/4+2πk,k∈z
sinx=1/√2⇒x=π/4+2πk U x=3π/1+2πk,k∈z