A dealer sold 200 pairs of gloves. Some were sold at $6 per pair and the remainder were sold at $11 per pair. Total receipts from this sale were $1600. How many pairs of gloves did he sell at $6 each.

Find the missing factor. 7s2 + 25s + 12 = (s + 3)( ).

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?