Answer
$427$
$f(x)=3x+1$
Work Step by Step
Each time a cut is made, $3$ extra pieces are formed. The first cut made gave $4$ pieces. So we can define the equation to be $f(x)=4+3(x-1)$ for $x$ cuts, simplified to $f(x)=3x+1$.
Using this equation, we can solve the first part of the problem. Plug in $142$ to get $f(142)=3(142)+1$, simplify to get $f(142)=427$.