Solve the following problems by setting up an equation or inequality.
a. if two numbers represented by (2m+1) and (2m+5) have a sum of 74, find m.
b. find two consecutive even numbers such that the sum of the smaller number and twice the greater number is 100.
c. if 9 is subtracted from a number, and the result is multiplied by 19, the product is 171. find the number.
d. the product of two consecutive whole numbers is less than the sum of the square of the smaller number and 13.