Represent the number 256 in both exponent and expanded form

Can someone pls ! pls answer all. no explanation needed..

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

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