standard_description: Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.
problem_activity: Task
The students in Mr. Sanchez's class are converting distances measured in miles to kilometers. To estimate the number of kilometers, Abby takes the number of miles, doubles it, then subtracts 20% of the result. Renato ﬁrst divides the number of miles by 5, then multiplies the result by 8.
Write an algebraic expression for each method.
Use your answer to part (a) to decide if the two methods give the same answer.


aligns: no