The number of nano-related patents that are granted in the us increases by a factor of 1.2 every year. in 1991 there were 60 nano-related patents.
which expression gives the number of patents in 1998?

The number of Nano - related patents in 1998 is 65.22

Step-by-step explanation:

Given as

The number of Nano - related patents in the year 1991 = 60

The rate of their increases by factor of 1.2 every year

So , the number of patents after 7 years in 1998 is :

Final Number = Initial number

Or,  Final Number = 60

Or, Final number  = 60

I.e Final number   = 65.22

Hence the number of patents in 1998 is 65.22  Answer

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225

answer is x<