Evaluate each expression.
4√81

What are the exclude value of mn+3m

(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.

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?