Respuesta :

Answer:

Representing the situation:

9. n + 12n = 91

18. n + 10n = 99

20. 12n +3 = 135

21. 8(n+7) = 104

26. 2(n+43) = 94

27. 60 + n = 132

Solving the equation:

9. n + 12n = 91

    13n = 91

    n = 91/13

    n = 7

18. n + 10n = 99

    11n = 99

    n = 99/11

    n = 9

20. 12n +3 = 135

     12n = 132

     n = 132/12

     n = 11

21. 8(n+7) = 104

    8n + 56 = 104

    8n = 48

    n = 6

26. 2(n+43) = 94

     2n + 86 = 94

     2n = 8

     n = 4

27. 60 + n = 132

     n = 72