#7(8a-7) = 11-4a#
#56a - 49 color(red)(+4a)= 11 color(red)(cancel(color(black)(-4a) +4a))#
#56a + 4a color(red)(cancel(color(black)(- 49) + 49))= 11 color(red)(+ 49)#
#(color(red)(cancel(color(black)(60)))a)/color(red)(cancel(60)) = 60/color(red)(60)#
#color(blue)(a = 1)#