a: \(\Leftrightarrow6\left(x+5\right)-8\left(2x-3\right)=3\left(6x-1\right)+2\left(2x-1\right)\)
=>6x+30-16x+24=18x-6+4x-2
=>-10x+54=22x-8
=>-32x=-62
=>x=31/16
b: \(\Leftrightarrow21\left(4x+3\right)-30\left(3x-1\right)=35\left(5x+4\right)+3\cdot105\)
=>84x+63-90x+30=175x+140+315
=>-7x+93=175x+455
=>-182x=-362
=>x=181/91
c: =>3(3x+2)-3x-1=10+12x
=>12x+10=9x+6-3x-1=6x+5
=>6x=-5
=>x=-5/6