Question

Find the interval(s) of numbers that are at least a distance of 3 away from "-7"

Answer 1

• x ≥ - 4 and x ≤ - 10 - as inequality
• ( - ∞, - 10] ∪ [ - 4, ∞) - as intervals

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The numbers that are at least a distance of 3 away from -7 are the numbers 3 units or more away from -7 either side on the number line :

• x ≥ - 7 + 3 = - 4

or

• x ≤ - 7 - 3 = - 10

This is same as:

• ( - ∞, - 10] ∪ [ - 4, ∞)