Question

Please help me solve for x.​

Answer 1

when running a line, in a right-triangle, from the 90° angle perpendicular to its opposite side, we will end up with three similar triangles, one Small, one Medium and a containing Large one. Check the picture below.

`\cfrac{9 + x}{15}=\cfrac{15}{9}\implies \cfrac{9 + x}{15}=\cfrac{5}{3}\implies 27+3x=75 \\\\\\ 3x=48\implies x=\cfrac{48}{3}\implies \boxed{x=16}`