Найдите значения функции y=f(x) в заданных точках: а) f(x)=1/3-5x; x=-0.5; 1/15; 0; б) f(x)=2/2+x, x=-1; 0; -1/5.

А)  f(x)=1/3-5x; x=-0.5
f(-0.5) = 1/3 - 5 * (-0.5) = 1/3 + 2.5 = 1/3 + 2 5/10 = 1/3 + 2 1/2 = 1/3 + 5/2 = (2+15)/6 = 17/6 = 2 5/6
f(1/15) = 1/3 - 5 * (1/15) = 1/3 - 1/3 = 0
f(0) = 1/3 - 5 * 0 = 1/3

Б) f(x)=2/(2+x), x=-1; 0;-1/5.
f(-1) = 2/(2-1) = 2
f(0)=2/(2-0) = 1
f(-1/5) = 2/(2-(-1/5)) = 2/(2+1/5) = 2/(10/5+1/5) = 2/(11/5) = 2 * 5/11 = 10/11