I am doing equations with Zero Product Rule and am stuck on two problems.

2y2 + 5y = -3

x2 = -3x

form you product, and set to zero.

The second I will do for you.

x^2+3x=0
x(x+3)=0 which means x is zero, or x=-3

The first will form a quadratic, and you can factor it into two factors.