Question

will give medal for explanation and answer thanks

Subtract and simplify: (3x2 + 7) – (x2 – 6x + 4)



A.


4x2 + 3


B.


2x2 + 6x + 3


C.


4x2 – 6x + 3


D.


2x2 + 6x + 11

Answer 1

@Haseeb96

Answer 2

There's an invisible "-1" on the second polynomial, you can view it like this:
\[(3x^2+7)+(-1)(x^2 -6x +4)\]
And using the distributive property of arithmetics:
\[3x^2+7-x^2+6x-4\]
Now, I will do something I like to call, "agrupating the coefficients" which consists of, looking at the variables that are alike, for example, the x^2, and draw "common factor" between them, thus, agrupating the coefficients and making them easily operable:
\[(3-1)x^2+6x +(7-4)\]
And operating the parenthesis:
\[2x^2+6x +3\]

Answer 3

thanks alot