Can you write an equation by setting an expression equal to itself?

Aline passes through the point (2, -4) and has a slope of 0, what is the equation of the line? plz fast

According to the 2008 u.s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of florida was approximately two times the population of california. b. the population of florida was approximately twenty times the population of california. c. the population of california was approximately twenty times the population of florida. d. the population of california was approximately two times the population of florida.

Which expression is rational? 6. , square root two, square root 14, square root 49