Polynomial operations

Find the sum.
(2x² + 5x - 7) + ( 3 - 4x² + 6x)

• 2x² + 3x +1
• -2x² - 11x -4
• 2x² + 5x -7
• -2x² + 11x -4

Find the difference. 
(3- 2x + 2x²) - (4x -5 +3x²)

• x_² + 6x + 8
• 2x² + 5x - 7
• -x² -6x + 8
• -2x² + 11x - 4

Simplify the expression.
-3x²( 7x² - x + 4)

• -21x⁴ + 3x³ -12x²
• 7x² - x + 4 (-3x²)
• 21x⁴ + 3x³ + 12x²
• -12x² + 3x³ -21x⁴

Multiply.
(b+3)(b²+2b+1)

• b³+6b²+6b+3
• b³+5b²+7b+3
• 4b³+8b²+3b
• 3b³+6b²+3b

(2x - 1)(x + 2)

• 2x² + 3x - 2
• 2x² - 5x - 2
• 2x² + 3x + 2
• 2x² - 5x + 2

What type of polynomial is 
 4x² - 21x + 5

• Monomial
• Binomial
• Trinomial
• Quadranomial