Solve the inequalities: a) (x−7)^3(x+2)^2(x−13)< 0 b) x^2(x+1)^3/(x−7)(x+3)^2(−x^2−1) ≤0

Given: and prove: what is the missing reason in the proof? given transitive property alternate interior angles theorem converse alternate interior angles theorem

When you answer this can you explain

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?