Domain and range and function , need ASAP

Trevor and marissa together have 26 t-shirts to sell. if marissa has 6 fewer tshirts that trevor, find hiw many tshirts trevor has. identify the if-than moves in your solution

Which addition property is being illustrated below? (type commutative or associative) (6 + 7) + 1 = 6 + (7 + 1)

(c) the diagram shows the first three shapes of a matchsticks arrangement.first shape = 3second shape = 5third shape = 7given m represents the number of matchstick used to arrange the n'th shape.(i) write a formula to represent the relation between m and n. express m as the subjectof the formula.(ii) 19 matchsticks are used to make the p'th shape. find the value of p.