Which two equations would be most appropriately solved by using the zero product property? Select each correct answer.
a) (x−3)(x+4)=0
b) x² + 3 = 16
c) −0.5x²−0.34x+9=0
d) 2x² + 6x = 0

Last year, laura had $30,000 to invest. she invested some of it in an account that paid 7% simple interest per year, and she invested the rest in an account that paid 8% simple interest per year. after one year, she received a total of $2230 in interest. how much did she invest in each account?