Any easier way to solve this than plugging each x value in?

Rhombus adef is inscribed into a triangle abc so that they share angle a and the vertex e lies on the side bc . what is the length of the side of the rhombus if ab=c, and ac=b.

Olga bought a new skirt that cost $20. sales tax is 5%. how much did olga pay, including sales tax? 7.

Which of the following choices gives you a slope of 3?