A 42-inch board is to be cut into three ploces so that the second ploco is twice as long as the first place and the third piece is 4 times as long as the first place. If x represents the length of the first pleco find the lengths of all three plocos
What is the length of the first piece?

Letter c so sorry if i’m wrong ):

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?