Question

1.folosind factorul comun ,calculati
a)25x37+63x25

b )45x32-32x1045
;c)57la putera a 2 -56 x57

d) 77 la puterea a doua - 78x77
e)99 la puterea a2-98x99-98
2.scoateti factor comun:
42.descompuneti in factori
si 41 sunt exercitile jos va rog frumos sa ma ajutati :*

Answer 1

a) 25 37 + 25 63 = 25 (37 + 63) = 25 100 = 2500
b) 45 32 - 32 1045 = 32 (45 - 1045) = 32 (-1000) = -32000
c) 57² - 56 57 = 57 57 - 56 57 = 57 (57 - 56) = 57 1 = 57
d) 77² - 78 77 = 77 77 - 78 77 = 77 (77 - 78) = 77 (-1) = -77
e) 99² - 98 99 - 98 = 99 99 - 98 99 - 98 = 99 (99 - 98) - 98 = 99 1 - 98 = 99 - 98 = 1.

41. a) x² + 6x + 8 = x + 2x + 4x + 8 = x (x + 2) + 4 (x + 2) = (x + 4) (x + 2)
b) x² - 10x + 9 = x² - x - 9x + 9 = x² - x + 9 - 9x = (-x) (1 - x) + 9 (1 - x) =
= (9 - x) (1 - x)
c) x² - 20x + 96 = x² - 8x - 12x + 96 = x (x - 8) - 12 (x - 8) = (x - 12) (x - 8)
d) x² - 8x - 9 = x² - 9x + x - 9 = x (x - 9) + (x - 9) = (x + 1) (x - 9)
e) x² - 14x + 24 = x² - 2x - 12x + 24 = x (x - 2) - 12 (x - 2) = (x - 12) (x - 2)
f) x² - 7x + 10 = x² - 2x - 5x + 10 = x (x - 2) - 5 (x - 2) = (x - 5) (x - 2)
g) x² - 15x + 56 = x² - 7x - 8x + 56 = x (x - 7) - 8 (x - 7) = (x - 8) (x - 7)
h) x² + 23x + 60 = x² + 20x + 3x + 60 = x (x + 20) + 3 (x + 20) = (x + 3) (x + 20)
i) x² + 17x - 60 = x² + 20x - 3x - 60 = x (x + 20) - 3 (x + 20) = (x - 3) (x + 20)