SOLUTION: Solve the inequality │2x - 3│≥ 1

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Question 1206735: Solve the inequality │2x - 3│≥ 1
Found 2 solutions by MathLover1, greenestamps:
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

abs%282x+-+3%29%3E=1

sqrt%282x+-+3%29%3E=1
=>
2x+-+3%3E=+1 =>2x+%3E=+1%2B3=>x+%3E=+4%2F2=>x+%3E=+2
or
-%282x+-+3%29%3E=+1=>-2x%2B3+%3E=1=>-1%2B3+%3E=2x=>2+%3E=2x=>2x+%3C=2=>x+%3C=1

solutions:
x+%3C=1
x+%3E=+2

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Answer by greenestamps(13198) About Me  (Show Source):
You can put this solution on YOUR website!


The response from the other tutor shows a perfectly good standard formal algebraic solution.

A very different method for solving the problem is often much easier than the standard algebraic method.

The expression abs%28x-a%29=b can be interpreted as saying the difference between x and a is equal to b. For example, abs%28x-5%29=3 means the difference between x and 5 is 3; that means x is either 5+3=8 or 5-3=2.

We can solve this problem using that method.

abs%282x-3%29%3E=1

Divide everything by 2, because we need "x" to be by itself:

abs%28x-1.5%29%3E=0.5

This absolute value inequality says that the difference between x and 1.5 is greater than or equal to 0.5.

1.5-0.5=1, so the difference between x and 1.5 is greater than or equal to 0.5 if x is less than or equal to 1;
1.5+0.5=2, so the difference between x and 1.5 is greater than or equal to 0.5 if x is greater than or equal to 2

So the inequality is satisfied if x is either less than or equal to 1, or greater than or equal to 2.

ANSWER: x%3C=1 or x%3E=2