7th grade math help. Find the perimeter. Do NOT include the units in your answer.

The weight of an object in a particular scale is 175.2 lbs. the measured weight may vary from the actual weight by at most 0.1 lbs. what is the range of actual weights of the object

The sum of the reciprocal of a positive number and the reciprocal of 2 more than the number is 3/4 equation: the number is

Satchi found a used bookstore that sells pre-owned dvds and cds. dvds cost $9 each, and cds cost $7 each. satchi can spend no more than $45.