Respuesta :

Answer:

Step-by-step explanation

7.

[tex]\frac{6}{6+6} =\frac{8}{8+8} =\frac{7}{x} \\\frac{1}{2} =\frac{7}{x} \\x=7*2=14[/tex]

9.

[tex]\frac{x+1}{12} =\frac{x-1}{8} \\12x-12=8x+8\\12x-8x=8+12\\4x=20\\x=20/4=5[/tex]