Question 12429
<font face = "courier new" size = 2>x²+y²=13
2x+y=1 
I then tried to solve by substitution: 
y=1-2x
x²+(1-2x)²=13 
I then got a bit muddled up and wasn't sure how to expand
(1-2x)²<font size = 3 color = "blue"><b> 
-----------
Then you went astray.  To expand (1-2x)², write it as
(1-2x) multiplied by itself:
`
(1-2x)² = (1-2x)(1-2x)
`
Now use "FOIL" on that.  You'll eventually end up with a quadratic
equation which can be solved by factoring.  You'll get two answers
for x, and then you'll substitute each of these into y=1-2x to get
the corresponding values for y.
`
If you still have trouble
post again.  I'll give you the answers:
`
There are two solutions
`
(2, -3) and (-6/5, 17/5)  
`
Edwin