Solve problems 3, 7, 15, 17, 19, 20, 21

3. | -9 | = 9

7. - | -5 * -7 | = - | 35 | = -35

15. | m + 3 | = 7
    
      m + 3 = 7          -(m + 3) = 7
      m = 7 - 3           -m - 3 = 7
      m = 4                -m = 10
                                m = -10

       so m = 4 and m = -10

17. | -3d | = 15
  
      -3d = 15               -(-3d) = 15
         d = 15/-3               3d = 15
         d = - 5                    d = 15/3
                                        d = 5
     
         so d = 5 and d = -5

19. | 4b - 5 | = 19
  
      4b - 5 = 19             -(4b - 5) = 19
      4b = 19 + 5            -4b + 5 = 19
      4b = 24                   -4b = 14
        b = 24/4                  b = 14/-4
        b = 6                       b = - 7/2

         so b = 6 or b = -7/2

20. | x - 1 | + 5 = 2
      | x - 1 | = 2 - 5
      | x - 1 | = -3
There is no solution on this one because an absolute value cannot equal a negative number

21. -4 | 8 - 5n | = 13
          | 8 - 5n | = - 13/4
  There is also no solution for this one because of the same reason...absolute values cannot equal negative numbers

21/2 or 5/2

1.) 18+5 is one way i’m pretty sure there are others but i can’t think of them right now