Factorise fully:
21a-7a²
if you can solve this thanks ive struggled on it for a while now

Which of the fallowing best completes the sequence 5,10,15, a) 30 b) 22 c)25 d)35

Which sentence describes why polygon mnop is congruent to polygon jklp? a. polygon jklp maps to polygon mnop through a translation. b. polygon jklp maps to polygon mnop through a rotation. c. polygon jklp maps to polygon mnop through a dilation. d. polygon jklp maps to polygon mnop through a stretch.

1. the wheeling bridge in west virginia is about 307 meters long. if you walk with a stride of about meter, about how many steps would it take you to cross this suspension bridge?