#2
f(x) = - 3x - 4/7
а) Если х = - 6/7, то f(x) = f(- 6/7) = - 3 • (- 6/7) - 4/7 = 3 • 6/7 - 4/7 = 18/7 - 4/7 = 14/7 = 2;
б) Если f(x) = 3/7, то f(x) = - 3x - 4/7 = 3/7.
- 3x - 4/7 = 3/7
- 3x = 3/7 + 4/7
- 3x = 1
x = 1 : (- 3)
x = - 1/3
Ответ: а) 2; б) - 1/3.