In a rhombus, all sides are equal:
5x = 15
and x = 15/5 = 3
(you could have done the same thing with the other side: 5x = 4x +3)
Answer:Learn how to write a proportional equation y=kx where k is the so-called "constant of proportionality".
Step-by-step explanation:
https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-ratio-proportion/cc-7th-equations-of-proportional-relationships/v/equations-of-proportional-relationships#:~:text=Learn%20how%20to%20write%20a,called%20%22constant%20of%20proportionality%22.
