Which polynomial represents the sum below?(16x2 - 16) + (-12x2 - 12x + 12) A. 4x2 - 12x + 28 B. 28x2 - 28x - 12 C. 16x2 - 28x - 16 D. 4x2 - 12x - 4
Question
Answer:
The correct answer is: [D]: " 4x² − 12x − 4 " .___________________________________________________
Explanation:
___________________________________________________
Given:
___________________________________________________
" (16x² − 16) + ( -12x² − 12x + 12) " ; Simplify.
___________________________________________________
Note the "distributive property of multiplication:
___________________________________________________
a(b + c) = ab + ac ;
a(b − c) = ab − ac .
___________________________________________________
So we can rewrite the expression as:
" (16x² − 16) + 1( -12x² − 12x + 12) " ;
{The "1" is implied; since "1", multiplied by any value, results in the exact same value.}.
Let us examine the following part of the expression:
_________________________________________________
" + 1 ( -12x² − 12x + 12 ) " ;
Using the distributive property of multiplication:
" + 1 ( -12x² − 12x + 12 ) = (1 * -12x²) − (1 * 12x) + (1 * 12) ;
= " − 12x² − 12x + 12 " ;
_________________________________________________
Now, bring down the other part of the expression; & rewrite:
_________________________________________________
→ " (16x² − 16) − 12x² − 12x + 12 " ;
→ " 16x² − 16 − 12x² − 12x + 12 " ;
Now, combine the "like terms" :
+ 16x² − 12x² = 4x² ;
− 16 + 12 = -4 ;
and we have " − 12x" ;
So we can rewrite the expression as:
_______________________________________________________
→ " 4x² − 12x − 4 " ;
→ which is: "Answer choice: [D]: " 4x² − 12x − 4 " .
_______________________________________________________
solved
general
11 months ago
4152