Question

Choose the correct simplification of (2x3 + x2 − 4x) − (9x3 − 3x2).

Answer 1

2x^3 + x^2 - 4x - (9x^3 - 3x^2) =
2x^3 + x^2 - 4x - 9x^3 + 3x^2 =
-7x^3 + 4x^2 - 4x <===

Answer 2

Answer:

option (2) is correct.

$(2x^3+x^2-4x)-(9x^3-3x^2)=-7x^3+4x^2-4x$

Step-by-step explanation:

Given  expression $(2x^3+x^2-4x)-(9x^3-3x^2)$

We have to choose the correct option that correctly simplify the given expression.

       

Consider the given expression $(2x^3+x^2-4x)-(9x^3-3x^2)$

Opening the brackets , we get,

Applying plus-minus rule, $-(-a)=+a$

$(2x^3+x^2-4x)-(9x^3-3x^2)=2x^3+x^2-4x-9x^3+3x^2$

LIKE TERMS are terms having same variable with same degree.

Adding like term , we get,

$(2x^3+x^2-4x)-(9x^3-3x^2)=(2-9)x^3+(3+1)x^2-4x$

$(2x^3+x^2-4x)-(9x^3-3x^2)=-7x^3+4x^2-4x$

Thus, option (2) is correct.