Need help with these two thats all.

Use the knowledge of x- and y- intercepts to choose the correct graph of the equation 3x+6y=6

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.

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base