1) Подставляем х=1/6:(2+1/(21/6))(3-1/(31/6)) = (2+3)(3-2) = 5
2) a) 5b^2/(b-c) - 5c^2/(b-c) = 5(b^2-c^2)/(b-c) = 5(b+c)(b-c)/(b-c) = 5(b+c)b) (x^2 + 4x + 4)/x^2 (2-x)/(2+x) = ((x+2)^2)/x^2 (2-x)/(2+x) = (x+2)(2-x)/(x*(2+x)) = (2-x)/(x+2)
1) Подставляем х=1/6:
(2+1/(21/6))(3-1/(31/6)) = (2+3)(3-2) = 5
2) a) 5b^2/(b-c) - 5c^2/(b-c) = 5(b^2-c^2)/(b-c) = 5(b+c)(b-c)/(b-c) = 5(b+c)
b) (x^2 + 4x + 4)/x^2 (2-x)/(2+x) = ((x+2)^2)/x^2 (2-x)/(2+x) = (x+2)(2-x)/(x*(2+x)) = (2-x)/(x+2)