Help. Please

Explain?show work?

Help with number 2&3

2) I believe that this is false. The amount of interest is the amount of extra money that has to be paid (total interest). The interest rate is how you calculate that.

3) true, because decimal equations are simpler.

b.an increase in a causes b to decrease

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225