How do you find the null hypothesis when you have the alternative hypothesis?

Find the sum of 4x^{2} -4+6 and -7^{2} +3x+1

Is it true that product of 3 consecutive natural numbers is always divisible by 6? justifyyour answer

Which number is located at point a on the number line? a number line is shown from negative 10 to 10 with each interval mark on the number line representing one unit. point a is labeled one interval mark to the right of negative 5.