First, add and subtract the necessary terms from each side of the equation to isolate the #n# terms on one side of the equation and the constants on the other side of the equation while keeping the equation balanced:
#6n - 4 + color(red)(4) - color(blue)(n) = n + 11 + color(red)(4) - color(blue)(n)#
#6n - color(blue)(n) - 4 + color(red)(4) = n - color(blue)(n) + 11 + color(red)(4)#
#(6 - 1)n - 0 = 0 + 15#
#5n = 15#
Next, divide each side of the equation by #color(red)(5)# to solve for #n# while keeping the equation balanced:
#(5n)/color(red)(5) = 15/color(red)(5)#
#(color(red)(cancel(color(black)(5)))n)/cancel(color(red)(5)) = 3#
#n = 3#