Kobe bought a bag of chocolate for $26.80 and some cookies that cost $.75 each. He paid a total of $37.30 for these items. Help me with this

Which is a true statement comparing the graphs of x^2/6^2-y^2/8^2 = 1 and x^2/8^2-y^2/6^2 the foci of both graphs are the same points. the lengths of both transverse axes are the same. the directrices of = 1 are horizontal while the directrices of = 1 are vertical. the vertices of = 1 are on the y-axis while the vertices of = 1 are on the x-axis.

Select the margin of error that corresponds to the sample mean that corresponds to each population: a population mean of 25, a standard deviation of 2.5, and margin of error of 5%

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?