Respuesta :

Answer

The missing length is 10

Step-by-step explanation:

Represent the missing length with x

The sides of the given shape are directly proportional.

Mathematically:

(15 + x) to (12 + 8) and x to 7

Represent as a ratio:

[tex](15 + x) : (12 + 8) = x : 8[/tex]

[tex]15 + x : 20= x : 8[/tex]

Convert to fraction

[tex]\frac{15 + x}{20} = \frac{x}{8}[/tex]

Cross Multiply:

[tex](15 + x)*8 = 20 * x[/tex]

[tex]120 + 8x = 20x[/tex]

Collect Like Terms

[tex]20x - 8x = 120[/tex]

[tex]12x = 120[/tex]

Solve for x

[tex]x = \frac{120}{10}[/tex]

[tex]x = 10[/tex]

The length of the missing side is 10