Question

va roggg...urgentttttt

Answer 1

(a + b) · (a - b) = 
= a² - ab + ba - b² = 
= a² - ab + ab - b² = 
= a² - b².

(a + b)² =
= a² + 2ab + b².

a) (4x + 9y) · (4x - 9y) =
= 16x² - 36xy + 36yx - 81y² = 
= 16x² - 36xy + 36xy - 81y² = 
= 16x² - 81y².

b) (2x + 3y) · (2x - 3y) · 5 = 
= (4x² - 6xy + 6yx - 9y²) · 5 = 
= (4x² - 9y²) · 5 =
= 20x² - 45y².

c) (x - 2)² = 
= x² - 2 · x · 2 + 2² = 
= x² - 4x + 4.

d) (2x + 1)² = 
= (2x)² + 2 · 2x · 1 + 1² = 
= 4x² + 4x +1.

e) (x + 4)² = 
= x² + 2 · x · 4 + 4² = 
= x² + 8x + 16.

(x + 4)² - y² = 
= (x + 4 + y) · (x + 4 - y) = 
= x² + 4x - xy + 4x + 16 - 4y + yx + y4 - y² = 
= x² + 8x + 16 - y².

f) (x + 3) · (x + 4) = 
= x² + x4 + 3x + 12 = 
= x² + 7x + 12.

g) (x + 4) · (x - 6) = 
= x² - x6 + 4x - 24 = 
= x² - 2x - 24.

/robertinni