Question

efetue


a) (x+1)(x+3)


b) (3x+2)(3x-2)


c) (2x+5)(3x-4)

(2
d) (x+1)(x -x+ 1 )

( 2
e) (2y+1)(3y-2y-11)

f) (x+2y)(x+y-5)

Answer 1

a) (x+1)(x+3) = x² + 3x + x + 3 = x² + 4x + 3

b) (3x+2)(3x-2) = 9x² - 6x + 6x - 4 = 9x² - 4

c) (2x+5)(3x-4) = 6x² - 8x + 15x - 20 = 6x² - 7x - 20

d) (x+1)(x -x+ 1) = x (x + 1) - x (x + 1) + (x + 1) = x² + x - x² - x + x + 1 = x + 1

e) (2y+1)(3y-2y-11) = 3y (2y + 1) - 2y (2y + 1) - 11(2y + 1) = 6y² + 3y - 4y² - 2y - 22y - 11 = 2y² - 21y - 11

f) (x+2y)(x+y-5) = x (x + 2y) + y (x + 2y) - 5 (x + 2y) = x² + 2xy + xy + 2y² - 5x - 10y = x² + 2y² + 3xy - 5x - 10y