a) 5. (3-2x)+5. (x-4)=6-4x
=> 15-10x+5x-20=6-4x
=> 15-10x+5x-20-6+4x=0
=> -11-x=0
=> x=-11
b)-3.(x-5)+6.(x+2)=9
=> -3x+15+6x+12=9
=> -3x+15+6x+12-9=0
=> 3x+18=0
=> 3x=-18
=> x=-6
c) 10.(x-7)-8.(x+5)=6.(-5)+24
=>10x-70-8x-40=-6
=> 10x-70-8x-40+6=0
=> 2x-104=0
=> 2x=104
=> x=52
d)-7.(3x+5)+2.(7x-14)=28
=> -21x-35+14x-28=28
=> -21x-35+14x-28-28=0
=> -7x-91=0
=> -7x=91
=> x=-13