Who knows math and can help me answer these?!

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

Select the correct answer from the drop-down menu. subtracting 3xy^2 from 8xy^2 gives the same result as the expression. [tex]3xy ^{2} - 8xy ^{2} [/tex][tex] { - 7xy}^{2} - {2xy}^{2} [/tex][tex] {7xy}^{2} - {2xy}^{2} [/tex]

If sr is 4.5cm and tr is 3cm, what is the measure in degrees of angle s?