\[\boxed{\text{417.}\text{\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]
\[B(2; - 1);\ \ y = f(x).\]
\[\textbf{а)}\ f(x) = kx + 1\]
\[- 1 = 2k + 1\]
\[2k = - 2\]
\[k = - 1.\]
\[\textbf{б)}\ f(x) = 2x + k\]
\[- 1 = 4 + k\]
\[k = - 5.\]