What is y intercept of 1x+3=y

Which rational number could be graphed between -4 and -5

My math teacher told my class to "steal" a 6th grade fraction word problem from the internet, word problems? : -p requirements: only a 1 step word problem. needs to be complex.

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)