The asseigment that i am doing is kinda hard can i get some help and i am in 7th grade

What is not true about kl and mn? what is mn? (show )

If f(x) = -5x + 1 and g(x) = x3, what is (gºf)(0)? enter the correct answer

Two cities a and b are 1400km apart and lie on the same n-s line. the latitude of city a is 23 degrees. what is the latitude of city b. the radius of the earth is approximately 6400km.