Simplify the following expression to an answer with only positive exponents.

[tex]\[
\frac{\left(2 x^5 y^7\right)\left(-5 x^4 z^{-5}\right)}{y^{12} z^6}
\][/tex]

A. [tex]\(-\frac{10 z^9}{y^{17} z}\)[/tex]

B. [tex]\(-10 x^9 y^5 z^{11}\)[/tex]

C. [tex]\(-\frac{10 x^9}{y^3 z^{11}}\)[/tex]

D. [tex]\(-\frac{10 x^{20}}{y^4 z^{30}}\)[/tex]



Answer :

Sure, let's simplify the given expression step by step. We have:

[tex]\[ \frac{\left(2 x^5 y^7\right)\left(-5 x^4 z^{-5}\right)}{y^{12} z^6} \][/tex]

Step 1: Simplify the numerator.

First, multiply the terms in the numerator:

[tex]\[ \left(2 x^5 y^7\right)\left(-5 x^4 z^{-5}\right) \][/tex]

To multiply these, combine the coefficients and the variables with the same base:

[tex]\[ 2 \cdot -5 = -10 \][/tex]

For the exponents, we add the exponents of the same variables:

[tex]\[ x^{5+4} = x^9 \][/tex]
[tex]\[ y^{7} \][/tex]
[tex]\[ z^{-5} \][/tex]

So, the simplified numerator is:

[tex]\[ -10 x^9 y^7 z^{-5} \][/tex]

Step 2: Combine with the denominator.

Next, we divide the simplified numerator by the denominator:

[tex]\[ \frac{-10 x^9 y^7 z^{-5}}{y^{12} z^6} \][/tex]

For the variables in the numerator and the denominator, we subtract the exponents of the same bases:

[tex]\[ y^{7-12} = y^{-5} \][/tex]
[tex]\[ z^{-5-6} = z^{-11} \][/tex]

So, now we have:

[tex]\[ -10 x^9 y^{-5} z^{-11} \][/tex]

Step 3: Convert negative exponents to positive by moving them to the denominator.

[tex]\[ y^{-5} = \frac{1}{y^5} \][/tex]
[tex]\[ z^{-11} = \frac{1}{z^{11}} \][/tex]

So, the simplified expression is:

[tex]\[ \frac{-10 x^9}{y^5 z^{11}} \][/tex]

Therefore, the correct answer is:

[tex]\[ \boxed{-\frac{10 x^9}{y^5 z^{11}}} \][/tex]

From the given options, this matches:

D. [tex]\(\boxed{-\frac{10 x^9}{y^5 z^{11}}}\)[/tex]