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