Is subtraction. the correct operation to compare media's best and worst times? explain number 4

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?

Solving algebraic equations 2m+3=11