First, multiply each side of the equation by #color(red)(42)# to eliminate the fractions. #color(red)(42)# is the Lowest Common Denominator for the two fractions:
#color(red)(42) xx (n - 10)/6 = color(red)(42) xx 10/7#
#cancel(color(red)(42))7 xx (n - 10)/color(red)(cancel(color(black)(6))) = cancel(color(red)(42))6 xx 10//color(red)(cancel(color(black)(7)))#
#7(n - 10) = 60#
#(7 xx n) - (7 xx 10) = 60#
#7n - 70 = 60#
Next, add #color(red)(70)# to each side of the equation to isolate the #n# term while keeping the equation balanced:
#7n - 70 + color(red)(70) = 60 + color(red)(70)#
#7n - 0 = 130#
#7n = 130#
Now, divide each side of the equation by #color(red)(7)# to solve for #n# while keeping the equation balanced:
#(7n)/color(red)(7) = 130/color(red)(7)#
#(color(red)(cancel(color(black)(7)))n)/cancel(color(red)(7)) = 130/7#
#n = 130/7#