Tìm x, biết: a) 3^x + 3^(x + 1) + 3^ (x + 2) = 117; b) (0,4x - 2) - (1,5x + 1) - (-4x - 0,8) = 3,6

Tim x :
a) 3^x + 3^(x+1) + 3^ (x+2) = 117
b) ( 0,4 x - 2 ) - ( 1,5x + 1 ) - ( -4x - 0,8 ) = 3,6
c) ( 3/4x + 5 ) - ( 2/3x - 4 ) - ( 1/6x + 1 ) = ( 1/3x + 4 ) - ( 1/3x - 3)
d) | 2/3 - 2x | = 5/6