Can somebody give me the answer for question 13 ?

Points d and e are midpoints of the sides of triangle abc. the perimeter of the triangle is 48 units. what is the value of t? ο ο ο ο 7t +

Write the expression in simplified radical form. show all steps and work including any foil method work. (hint: use the conjugate. no decimal answers.) (9-2√3)/(12+√3)

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =