Sagot :
a) 7x+3+5x+6 = 12x + 9 = 3*( 4x+3)
b) -4y+9-5y-7 = 2 - 9y
c) 8a-9-12a+3 = -4a - 6 = - 2 (2a +3)
d) 15b²+3b-9b²-5 = 6 b^2 + 3 b -5 = 3 b (2b+1) - 5
b) -4y+9-5y-7 = 2 - 9y
c) 8a-9-12a+3 = -4a - 6 = - 2 (2a +3)
d) 15b²+3b-9b²-5 = 6 b^2 + 3 b -5 = 3 b (2b+1) - 5