SOLUTION: write √45 in the form k√5, where k is an integer

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Question 288382: write √45 in the form k√5, where k is an integer
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
Solved by pluggable solver: Simplifying Square Roots (whole numbers only)
Start with the given expression


The goal of simplifying expressions with square roots is to factor the radicand into a product of two numbers. One of these two numbers must be a perfect square. When you take the square root of this perfect square, you will get a rational number.

So let's list the factors of 45

Factors:

1, 3, 5, 9, 15, 45



Notice how 9 is the largest perfect square, so lets factor 45 into 9*5





Factor 45 into 9*5



Break up the square roots using the identity



Take the square root of the perfect square 9 to get 3



So the expression simplifies to



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Check:

Notice if we evaluate the square root of 45 with a calculator we get





and if we evaluate we get





This shows that . So this verifies our answer




Since , this means that