If a(x)=c^2-1 and b(x)=c^2+1, then which statement is not true?

(1) a(x)*b(x)=c^3+c^2-c-1
(2) a(x)+b(x)=c^2+c
(3) a(x)-b(x)=c^2-c-2
(4) a(x) / b(x)=c+1

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula c= r/1.8 - 273, what is the temperature in celcius corresponding to r degrees rankine.

Which representation has a constant of variation of -2.5

What is the result of adding the system of equations? 2x+y=4 3x-y=6