So-called simplifying, really means, "rationalizing the denominator", which is another way of saying, "getting rid of that pesky radical in the bottom"
Is this some sort of cryptic message?
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Answer:
.
Step-by-step explanation:
First, let's see how 23 compares with the squares of the positive whole numbers on the number line.
1² = 1
2² = 4
3² = 9
4² = 16
5² = 25
The value of 23 is right between the square of 4 and the square of 5. Thus, the value √23 will be between 4 and 5.
Since 23 is much, much closer to the square of 5 than the square of 4, we can assume that the value √23 will be closer to 5 on the number line than 4.
Look at the attached image to see where I plotted the approximate location of √23.
You will realize that this approximation is pretty close since the actual value is roughly 4.80.
Let me know if you need any clarifications, thanks!

y - y₁ = m(x - x₁)
y - (-10) = -1⁴/₂₁(x - 6)
y + 10 = -1⁴/₂₁(x) + 1⁴/₂₁(6)
y + 10 = -1⁴/₂₁x + 7¹/₇
- 10 - 10
y = -1⁴/₂₁x - 3¹/₇