What is the value of x in this equation: 4x + 5 = 3x +4

What are the domain and range of the function? f(x) = -4 (sqrt)x

Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. the mean arrival rate is 10 passengers per minutes. compute the following probabilities. p(x = 4) p(x > 11)

What is the answer to this question? i'm a bit stumped. also how do i do it? 5(x - 4) = 2(x + 5)