(2) For the rule $y=3 x-4$, find the value of $y$ for these $x$-values. a $x=2$ b $x=-1$

Step 1 ：We are given a linear equation \(y=3x-4\) and we need to find the value of \(y\) for \(x=2\) and \(x=-1\).

Step 2 ：We can substitute these values of \(x\) into the equation to find the corresponding \(y\) values.

Step 3 ：For \(x=2\), substituting into the equation gives \(y=3*2-4=2\).

Step 4 ：For \(x=-1\), substituting into the equation gives \(y=3*(-1)-4=-7\).

Step 5 ：Final Answer: For \(x=2\), \(y\) is \(\boxed{2}\) and for \(x=-1\), \(y\) is \(\boxed{-7}\).