Step 1) Multiply each side of the equation by #color(red)(d)# to eliminate the fraction on the side of the equation with the #c# variable while keeping the equation balanced:
#color(red)(d)(5/(3a) + 4b) = color(red)(d)((1 - 2c)/d)#
#(color(red)(d) xx 5/(3a)) + (color(red)(d) xx 4b) = cancel(color(red)(d))((1 - 2c)/color(red)(cancel(color(black)(d))))#
#(5d)/(3a) + 4bd = 1 - 2c#
Step 2) Subtract #color(red)(1)# from each side of the equation to isolate the #c# term while keeping the equation balanced:
#(5d)/(3a) + 4bd - color(red)(1) = -color(red)(1) + 1 - 2c#
#(5d)/(3a) + 4bd - 1 = 0 - 2c#
#(5d)/(3a) + 4bd - 1 = -2c#
Step 3) Divide each side of the equation by #color(red)(-2)# to solve for #c# while keeping the equation balanced:
#((5d)/(3a) + 4bd - 1)/color(red)(-2) = (-2c)/color(red)(-2)#
#(5d)/(color(red)(-2) xx (3a)) + (4bd)/color(red)(-2) - 1/color(red)(-2) = (color(red)(cancel(color(black)(-2)))c)/cancel(color(red)(-2))#
#-(5d)/(6a) - 2bd + 1/2 = c#
#c = -(5d)/(6a) - 2bd + 1/2#