<PRE><B>Question 466773</B>
x=61-9y
-7x+7y=-7
-7*(61-9y)+7y=-7
-427+63y+7y=-7
70y=420
y=6
--------------
-7x+7*6=-7
-7x+42=-7
-7x=-49
x=7
-------------
7+9*6=61
</PRE>