Andy C. answered 03/26/18
Tutor
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Math/Physics Tutor
7x - 3 >= 5 OR 7x-3 <= -5
7x >= 8 OR 7x <= -2
x >= 8/7 OR x <= -2/7
closed circle at -2/7 then shade left
closed circle at 8/7 then shade right
CHECK:
-1 is in the first set: | 7(-1) - 3| =| -7 - 3 | = |-10| = 10 >= 5 ; yes it works
2 is in the second set: | 7(2) - 3 | = | 14 - 3 | = | 11 | = 11 >= 5 ; yes it works
zer0 is NOT in either set: | 7(0) - 3 | = | 0 - 3 | = | -3 | = 3 < 5 ; No, it fails as expected
Moreover, For x = -2/7, | 7(-2/7) - 3 | = | -2 - 3 | = | -5 | = 5 >= 5 ; yes it works
For x = 8/7, | 7(8/7) - 3 | = | 8 - 3 | = | 5 | = 5 >= 5 ; yes it works