Fill in the blanks to make the statements true:

(a + b)² - 2ab = ……… + ……… .

Fill in the blanks to make the statements true:

a² – b² = (a + b) …………… .

Fill in the blanks to make the statements true:

(a – b)² + ……….. = a² – b²

Fill in the blanks to make the statements true:

(x + a) (x + b) = x² + (a + b)x + ……….. .

Fill in the blanks to make the statements true:

The product of two polynomials is a ………. .