If you have two unknown quantities, then you need two equations
in order to find their values.
If there's only one equation, then the graph of that equation is a
straight line with no ends. EVERY POINT on that line is a pair of
numbers that can be the values of 'x' and 'y'.
(And I think you know how many points there are on a line.)
Here are a few correct answers to your question:
x = -10
,
y = 26.5
x = -9
,
y = 23
x = -8
,
y = 19.5
x = -7
,
y = 16
x = -6
,
y = 12.5
x = -5
,
y = 9
x = -4
,
y = 5.5
x = -3
,
y = 2
x = -2
, y = -1.5
x = -1
, y = -5
x = 0
, y = -8.5
x = 1
, y = -12
x = 2
, y = -15.5
x = 3
, y = -19
x = 4
, y = -22.5
x = 5
, y = -26
x = 6
, y = -29.5
x = 7
, y = -33
x = 8
, y = -36.5
x = 9
, y = -40
x = 10
, y = -43.5
Now, with those 21 correct answers out of the way,
there are only an infinite number of others.
