Tìm x, biết: a) (3x - 1).(2x + 7) - (x + 1).(6x - 5) = 16; b) (10x + 9).x - (5x - 1).(2x + 3) = 8

Tìm x:
a.(3x-1).(2x+7)-(x+1).(6x-5)=16
b.(10x+9).x-(5x-1).(2x+3)=8
c.(3x-5).(7-5x)+(5x+2).(3x-2)-2=0
d.x.(x+1).(x+6-x^3)=5x