Question

descompuneti in factori c) x² +6x+9 d) x²-4x+4 e) x²-25
f) 4x²+4x+1 g)9x² +12x+4 h) 9x²-25 i) x²+10x+16 j)x²+5x+6 k) x²-2x-15
dau coroană!!!​

Answer 1

c) x² + 6x + 9 = (x + 3)²

d) x² - 4x + 4 = (x - 2)²

e) x² - 25 = (x - 5)(x + 5)

f) 4x² + 4x + 1 = (2x + 1)²

g) 9x² + 12x + 4  = (3x + 2)²

h) 9x² - 25 = (3x - 5)(3x + 5)

i) x² + 10x + 16 =

= x² + 8x + 2x + 16

= x(x + 8) + 2(x + 8)

= (x + 2)(x + 8)

j) x² + 5x + 6 =

= x² + 3x + 2x + 6

= x(x + 3) + 2(x + 3)

= (x + 2)(x + 3)

k) x² - 2x - 15 =

= x² + 3x - 5x - 15

= x(x + 3) - 5(x + 3)

= (x - 5)(x + 3)