Question:medium

If $540 = 2^x \times 3^y \times 5^z$, find the value of $x + y - z$.

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To compare exponents:
Always do prime factorization first.
Match bases and compare powers.
This method is common in factorization problems.
Updated On: Feb 26, 2026
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Solution and Explanation

Step 1: Understanding the Question:
The question asks us to find the value of the expression \(x + y - z\), where \(x\), \(y\), and \(z\) are the exponents of the prime factors 2, 3, and 5, respectively, in the prime factorization of the number 540.
Step 2: Key Formula or Approach:
The fundamental approach is to perform the prime factorization of 540. This means expressing 540 as a product of its prime factors. Once we have this form, we can compare it to the given expression \(2^x \times 3^y \times 5^z\) to determine the values of \(x\), \(y\), and \(z\).
Step 3: Detailed Explanation:
First, we find the prime factorization of 540 by repeated division:
\[ 540 = 10 \times 54
\] Now, we factorize 10 and 54 further:
\[ 10 = 2 \times 5
\] \[ 54 = 2 \times 27 = 2 \times 3 \times 3 \times 3 = 2 \times 3^3
\] Combining these factors, we get the prime factorization of 540:
\[ 540 = (2 \times 5) \times (2 \times 3^3)
\] \[ 540 = 2 \times 2 \times 3^3 \times 5 = 2^2 \times 3^3 \times 5^1
\] Now, we compare this result with the given equation: \(540 = 2^x \times 3^y \times 5^z\).
By comparing the exponents of the corresponding prime bases, we find:
\[ x = 2, \quad y = 3, \quad z = 1
\] Finally, we calculate the value of the expression \(x + y - z\):
\[ x + y - z = 2 + 3 - 1 = 4
\] Step 4: Final Answer:
The value of \(x + y - z\) is 4.
\[ \boxed{4} \]
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