Question

Help me out again lovely geniuses.​

Answer 1

Solution:

Since the triangles are similar:

• 9 + 6:20 = 9:x

Solving the equation:

• 9 + 6:20 = 9:x
• => 15:20 = 9:x
• => 3/4 = 9/x
• => 9/12 = 9/x
• => x = 12

The value of x is 12.

Answer 2

$\\ \tt\hookrightarrow \dfrac{9}{x}=\dfrac{9+6}{20}$

$\\ \tt\hookrightarrow \dfrac{9}{x}=\dfrac{15}{20}$

$\\ \tt\hookrightarrow \dfrac{9}{x}=\dfrac{3}{4}$

$\\ \tt\hookrightarrow 3x=36$

$\\ \tt\hookrightarrow x=12$