HELP FAST!! find a_(1) if d=-2 and a_(21)=18

Arunning track in the shape of an oval is shown. the ends of the track form semicircles. a running track is shown. the left and right edges of the track are identical curves. the top and bottom edges of the track are straight lines. the track has width 56 m and length of one straight edge 130 m. what is the perimeter of the inside of the track? (π = 3.14) 260.00 m 347.92 m 372.00 m 435.84 m

Choose the correct classification of 3x4 − 9x3 − 3x2 + 6. 5th degree polynomial 4th degree polynomial 9th degree polynomial 24th degree polynomial

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?