Answer all questions please for the histrogram go to the second photo

I’m stuck on this equation, anyone got the answer?

Which expression is equal to (21)(7)(3x) using the associative property? (21 · 7 · 3)x (7)(21)(3x) 32(7 + 3x) (3x)(7)(21)

Atype of plant is introduced into an ecosystem and quickly begins to take over. a scientist counts the number of plants after mmonths and develops the equation p(m)= 19.3(1.089)^m to model the situation. most recently, the scientist counted 138 plants. assuming there are no limiting factors to the growth of the plants, about how many months have passed since the plants werefirst introduced? a)o 6.1b)0.6.6c)10 72d)o 23.1