1) 1,2m^3n^3
2)21/11a^4b^8c^2
3)4x^10y^10z^10
4)-7,5a^13b^11c^2
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1)(tgα+ctgα)²=tg²α+2*tgα*ctgα+ctg²α=tg²α+2+ctg²α; tg²α+ctg²α=(tgα+ctgα)²-2=p²-2;
2) (1+tg²α)(1-sin²α)-sin²α=
=1/cos²α * (cos²α)-sin²α=
=1-sin²α=cos²α=1/10
1) (с-0,7)(с+0,7) 2) (4-k)(4+k)
3) (20-m)(20+m) 4)(t-15)(t+15)
5) (1,3-b)(1,3+b) 6) (y-4/9)(y+4/9)
7) (5x-2)(5x+2) 8) (5/6-8y)(5/6+8y)