Pls show all work

Determine whether each of the following languages is decidable or not. If it is decidable, construct and analyze a decider. Otherwise, prove that it is undecidable via Turing reduction. (a) L={M,x:M(x) halts within 2x steps } (b) L={M1,M2,x:M1(x) runs for strictly fewer steps than M2(x) does }. (If both computations loop, then neither takes strictly fewer steps than the other.) (c) L={M1,M2:L(M1)L(M2)}