Can someone please help me with this !!! it’s geometry

The axis of symmetry for the graph of the function f(x)=1/4^2+bx +10 is x=6. what is the value of b?

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.

Moira has a canvas that is 8 inches by 10 inches. she wants to paint a line diagonally from the top left corner to the bottom right corner. approximately how long will the diagonal line be?