50 points and brianliest: which of the following expressions is in its simplest form?

8m + 4n - 5mn + 7
15bd + 5 - 2b + 3d + 23
xy + 6xy2 - 7 + 12xy
35 - a2 - ab2 + ab - 2ab2

Each of the four sides of a swimming pool measures 9 meters. the pool is 5 meters deep. how much water will be needed to fill it completely? a. 45 cubic meters b. 81 cubic meters c. 225 cubic meters d. 405 cubic meters reset next

Write an expression that has three terms and simplifies to 4x - 7. identify the coefficient(s) and constant(s) in your expression

1. if events a and b are non-overlapping events, how do you find the probability that one or the other occurs? 2. what does it mean if p(a or b) equals 1?