Even numbers greater than 30 but less than 40

If you shift the linear parent function, f(x)=x, up 13 units, what is the equation of the new function?

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

Which of these equations, when solved, gives a different value of x than the other three? a9.1 = -0.2x + 10 b10 = 9.1 + 0.2x c10 – 0.2x = 9.1 d9.1 – 10 = 0.2x