A1. For which value of the parameter $m$ is the equation $\left(m^{2}-7 m+6\right) x^{2}-m x+m-2=0$ linear?
(A) 0
(B) 2
(C) 0 and 2
(D) 1 and 6
(E) -1 and -6
A1. The equation is linear if the leading coefficient in the written quadratic equation is equal to 0. Therefore, it must hold that: $m^{2}-7 m+6=0$ or $(m-1)(m-6)=0$. From this, we get the solutions $m=1$ and $m=6$.