Tìm x, biết

tìm x, biết 
a, 4xx-5-x-14x-3=5
b, 3x-4x-2=3xx-9-3
c, x-5x-4-x+1x-2=7
d, 5xx-3=x-25x-1-5
e, x-3x^2+3x + 9+x5-x^2=6x