ayudeme porfavor con esto
![](https://es-static.z-dn.net/files/dcd/b76cd5a231a5edec5d2cfaa25d721500.jpg)
Respuestas a la pregunta
Respuesta:
12. 5/20
13. 2
14. 4/12
15. 7/13/19
16. 12/14/16/18
17. 22/44
18. 44
19. 7
Explicación paso a paso:
12. x+(x+15)=25 x+15=5+15=20
2x=10
x =5
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13. 2(4)+2x=12
2x=12-8
2x=4
x=2
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14. 2(a)+2(3a)=32 a=4
2a+6a=32 3a= 3(4)=12
8a=32
a=4
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15. x+(x+6)+(x+12)=39 x=7
3x+18=39 x=7+6=13
3x=21 x=7+12=19
x=7
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16. 2x+(2x+2)+(2x+4)+(2x+6)=60 2x=12
8x+12=60 12+2=14
8x=48 12+4=16
x=6 12+6=18
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17. 2(a)+2(2a)=132 a=22
6a=132 2a=44
a=22
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18. 2(x)+2(x+4)=168 x=40
2x+2x+8=168 40+4=44
4x=160
x=40
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19. x/2+3x=14
4x=28
x=7