Which Polynomial represents the difference below?

5x²+9x+3

- (6x²-3x)

A. - x²+6x+3

B. - x²+12x+3

C. 5x²+3x+3

D. 5x²+6x+3

The answer is B

Step-by-step explanation:

5x² + 9x + 3 - (6x ² - 3x)

this is easier if you distribute the negative in front of the perenthesis so ...

5x² + 9x + 3 + (-6x² + 3x)

then you just combine the terms with the same variable and exponent

-x² + 12x + 3

5x² + 9x+3 - (6x²-3x)

1 Remove parentheses.

5x²+9x+3-6x²+3x

2 Collect like terms.

(5x² - 6x²) + (9x+3x) + 3

3 Simplify.

-x² + 12x+3 which is B