This is valid through the law of syllogism. If you swap lines 1 and 2, then you'll have this argument:
If I step on a beehive, then I will get stung.
If I get stung by a bee, then it will hurt.
Therefore, if I step on a beehive, then it will hurt
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So it's like connecting a chain together. Point A (stepping on the hive), leads to point B (getting stung), which leads to point C (getting hurt). We can take a shortcut to bypass point B to jump from A to C in one step. Check out the attached image for a visual of what I'm referring to.
For this case we have the following inequality:
To find the solution we follow the steps below:
We apply distributive property on the right side of inequality:
Adding 13 to both sides of the inequality we have:
We subtract 6x on both sides of the inequality:
Thus, we have that any value of "x" makes the inequality fulfilled. Thus, the solution is given by all real numbers.
Answer:
The solution set is (-∞,∞)