Desfaceți parantezele și reduceți termenii asemenea:

a) -13x-15y+9x- (19x+3y-12x)+7y
b) (5x-8y) - (11x+3y) - (-13x-5y)
c) (4x²-3y+2x) - (4x+6y-5x²) - (9x²-7y-3x)
d) (3a+4b-2c) + (-5a-6b+4c) - (4a-7b-5c)
e) (5x-3a+2b) - (4x-5a+6b) - (7a-6x-5b)

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a) 2(3a-4b) -3 (a-2b) +4 (-2a+3b)
b) 4(3x+2y) -5 (2x-3y) +3 (-4x-5y)
c) -3(x²-2) +6 (x²-1) -4 (x²+3) +2 (x²-4)
d) 3(5x-2y)-5(2x+y)+2(-3x-4y)-4(-x-3y)
e) 3(4a+5b) -5 (2a+3b) -4 (3a+4b)+2(-a-2b)

URGENT!​