Someone pls help me

What is the solution to the system of the equations? x = y - 3 x + 3y = 13

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 california was approximately two times the population of florida. b. the population of florida was approximately twenty times the population of california. c. the population of florida was approximately two times the population of california. d. the population of california was approximately twenty times the population of florida.

Shannon mary and john earn a weekly allowance ahannon earns the amount that is 2/3 of what john earns mary earns an amount that is 1 2/3 of what johns earns 20 dollars a week who eaens the greatest allowance and who earns the least