Answer :
Sure! Let's simplify the given expression step by step:
The expression we need to simplify is:
[tex]\[ 3 x^2 \left(7 x^2 - 9\right) \][/tex]
Step 1: Distribute [tex]\( 3 x^2 \)[/tex] into the parentheses.
First, multiply [tex]\( 3 x^2 \)[/tex] by [tex]\( 7 x^2 \)[/tex]:
[tex]\[ 3 x^2 \cdot 7 x^2 = 21 x^4 \][/tex]
Next, multiply [tex]\( 3 x^2 \)[/tex] by [tex]\( -9 \)[/tex]:
[tex]\[ 3 x^2 \cdot (-9) = -27 x^2 \][/tex]
Step 2: Combine the results of the distribution.
Putting it all together, we get:
[tex]\[ 21 x^4 - 27 x^2 \][/tex]
Therefore, the simplified expression is:
[tex]\[ 21 x^4 - 27 x^2 \][/tex]
So, the correct answer is:
[tex]\[ \boxed{D. 21 x^4 - 27 x^2} \][/tex]
The expression we need to simplify is:
[tex]\[ 3 x^2 \left(7 x^2 - 9\right) \][/tex]
Step 1: Distribute [tex]\( 3 x^2 \)[/tex] into the parentheses.
First, multiply [tex]\( 3 x^2 \)[/tex] by [tex]\( 7 x^2 \)[/tex]:
[tex]\[ 3 x^2 \cdot 7 x^2 = 21 x^4 \][/tex]
Next, multiply [tex]\( 3 x^2 \)[/tex] by [tex]\( -9 \)[/tex]:
[tex]\[ 3 x^2 \cdot (-9) = -27 x^2 \][/tex]
Step 2: Combine the results of the distribution.
Putting it all together, we get:
[tex]\[ 21 x^4 - 27 x^2 \][/tex]
Therefore, the simplified expression is:
[tex]\[ 21 x^4 - 27 x^2 \][/tex]
So, the correct answer is:
[tex]\[ \boxed{D. 21 x^4 - 27 x^2} \][/tex]
