#color(green)("Using first principles method")#
Subtract #color(blue)(c)# from both sides
#color(brown)(acolor(blue)(-c)=bx+c color(blue)(-c)#
#a-c=bx+0#
Divide both sides by #color(blue)(b)#
#color(brown)((a-c)/(color(blue)(b))=b/(color(blue)(b))xxx)#
But #b/b=1# giving
#(a-c)/b=x#
#x=(a-c)/b#
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(green)("Using shortcut method")#
Move #c# to the other side of = and change its sign from + to - (opposite action)
#a-c=bx#
As #b# is multiply move it to the other side of = and change it to divide (opposite action).
#(a-c)/b=x#
