Do you know how to solve x-7y=21
ok so umm help
your supposed to isolate the variable. in order to do that you get rid of 7y but getting y by itself, in order to get a variable( letters) by themselves you have to divide since two numbers together mean multiply you do the opposite and so you divide 7y by 7 and do that to the other side of the = sign.
we need one more equation to solve as there are two variables x and y.