The solution of x+b> -14 is x> -21. what is the value of b?

  b = 7

Step-by-step explanation:

You can start with either inequality, then add the required amount to make it look like the other one.

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Starting with x > -21

  x > -21

  x + 7 > -14 . . . . . add 7 to both sides

  b = 7 . . . . . . . . .  compare to the form x + b > -14

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Starting with x + b > -14

  x + b > -14

  x + b -7 > -21 . . . add -7 to both sides

  b -7 = 0 . . . . . . compare to the form x > -21. 0 is added to x.

  b = 7 . . . . . . . . add 7 to both sides