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