Can someone help me solve this and explain how to solve if possible please?

In the figure shown below, m < 40 and ab =8. which equation could be used to find x?

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

Astudy claims that the mean age of online dating service users is 40 years. some researchers think this is not accurate and want to show that the mean age is not 40 years. identify the null hypothesis, h0, and the alternative hypothesis, ha, in terms of the parameter μ. select the correct answer below: h0: μ≥40; ha: μ< 40 h0: μ≤40; ha: μ> 40 h0: μ≠40; ha: μ=40 h0: μ=40; ha: μ≠40