Please check my answers:

Graph the inequality.

3x+5y< or equal to 15

x^2+y^2>25

y>x^2-4

y< or equal to x^2+2

Graph the solution set of the system of inequalities or indicate that the system has no solution.

2x-y < or equal to -6

x+2y> or equal to 2

x+2y> or equal to 2

x-y< or equal to 0

x^2+y^2< or equal to 49

10x+5y< or equal to 50

Solve the problem.A person with no more than $4000 to invest plans to place the money in two investments, telecommunications and pharmaceuticals. The telecommunications investment is to be no more than 3 times the pharmaceuticals investment. Write a system of inequalities to describe the situation. Let x=amount to be invested in telecommunications and y=amount to be invested in pharmaceuticals.

I got:

x+y=4000

x< or equal to 3y

x> or equal to 0

y> or equal to 0