Solving Two Equations of First Degree in Two Variables Graphically and Algebraically: The Omitting and Substitution Meth

Zena wants to cheer up her fish Zizi by decorating its tank. To do so, she needs to calculate the base surface area of the tank, which is a rectangle. Zena recalls that the length of the rectangle is 3 cm more than its width, and twice the length is 9 cm less than five times the width. She uses algebraic methods to solve these equations, finding the length to be 8 cm and the width 5 cm. Finally, she calculates the surface area to be 40 square centimeters, demonstrating how to solve linear equations using substitution and elimination methods.

What are the dimensions of the tank's base after Zena solved the equations?

What is the formula for calculating the surface area of the rectangle, and what was the final result?