Please help with number 10 please ​

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

Consider the enlargement of the pentagon. what is the value of x, rounded to the nearest tenth? 2.1 centimeters 3.3 centimeters 7.0 centimeters 15.0 centimeters

Ahmed plans to add a rectangular sunroom to his house. the sunroom will have a length of 14 feet and a width of 10 feet, and the construction will cost $40 per square foot. how much more would the sunroom cost if it’s width were increased to 12 feet?