<span>tg(x+9π)=tg(9</span>π+x)=tg(8π+(π+x))=tg(π+x)=tgx.
x(y-7)-y(7-y)=x(y-7)+y(y-7)=(x+y)(y-7) возможно так...
1) (t-5)^2 = (t-5)(t-5)
2) x^2-5x+2x-10 = x(x-5)+2(x-5) = (x+2)(x-5)
3) 3x^2-5x-3x+5 = 3x(x-1)-5(x-1) = (3x-5)(x-1)
4) -x^2+4x-2x+8 = x(x+4)-2(x-4)
Тут нельзя так делать ♀️
5) (4x-3)(4x+3)
6) a(-5a+8)
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