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4) (4x2– x – 7) + (2x3+ 6x2– 11)
5)(2x3– x + 4) + (5x2– 6x – 5)
6)(3x2+ 2x + 1) – (x2– 3x + 4)
7)(2x2– 3x + 7) – (5x2+ 3x + 6)

4) 2x3 + 10x2−x−18

5) 2x3+5x2−7x−1

6) 2x2+5x−3

7) −3x2−6x+1

Step-by-step explanation:

4) (4x2 - x - 7) + (2x3+ 6x2– 11)

Combine Like Terms:

=4x2+−x+−7+2x3+6x2+−11

=(2x3)+(4x2+6x2)+(−x)+(−7+−11)

=2x3+10x2+−x+−18

5) (2x3– x + 4) + (5x2– 6x – 5)

Combine Like Terms:

=2x3+−x+4+5x2+−6x+−5

=(2x3)+(5x2)+(−x+−6x)+(4+−5)

=2x3+5x2+−7x+−1

6) (3x2+ 2x + 1) – (x2– 3x + 4)

Distribute the Negative Sign:

=3x2+2x+1+−1(x2−3x+4)

=3x2+2x+1+−1x2+−1(−3x)+(−1)(4)

=3x2+2x+1+−x2+3x+−4

Combine Like Terms:

=3x2+2x+1+−x2+3x+−4

=(3x2+−x2)+(2x+3x)+(1+−4)

=2x2+5x+−3

7)(2x2– 3x + 7) – (5x2+ 3x + 6)

Combine Like Terms:

= (2x2 −5x2 )+(−3x−3x)+(7−6)