1. (-10)*(-2) . (-7-3) = умножение минум на минус плюс = 20/(-10)=-2
2/ (0.7 - 7/30) * 5/6 = (7/10 - 7/30)*5/6 = (21/30 - 7/30)*5/6 = 14/30*5/6 = 7/18
3/ 13.7*2.5 + 14.3*2.5 = 2.5(13.7+14.3) = 2.5*28 = 70
4/ 5^16 * 0.2^14 = 5^16/5^14 = (0.2=1/5)= 5^(16-14) = 5^2=25
5/ (3-x) - (x-4)=3
3-x - x+4=3
-2x = -4
x=2
6/ a^3 + 27b^3 = a^3 + (3b)^3 = (a+3b)(a^2 - 3ab + 9b^2)
a^3+b^3=(a+b)(a^2 - ab + b^2)
7/ y^3+3 - (y+2)(y-2y+4) = y^3+3 - (y^3+2^3) = y^3+3 - y^3 - 8 = -5
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на все 5 минут 45 секунд