What is the value of x?

enter your answer in the box.

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

Maurice has 54 fewer comic books than rebecca.they have 130 comic books together .how many comic books are in maurices collection ? how many comic books are in rebeccas collection