Posted by mysterychicken on Friday, May 6, 2011 at 2:35pm.
40. The graph of the following system yields perpendicular lines.
x + 2y = 10
4y = 2x + 20
(True?)
47. The graph of the following system yields parallel lines.
2y = 10 + x
4y = 2x + 20
(True)
48. The graph of the following system yields parallel lines.
x  2y = 1
y = 3x + 10
(False)
Are these correct?
Thanks
MC

Algebra  Reiny, Friday, May 6, 2011 at 5:05pm
47.
2y = 10 + x > y = (1/2)x  5
4y = 2x + 20 > y = (1/2)x  5
one slope is 1/2 then other is 1/2, so NOT parallel
your best way is to rewrite in the form
y = mx + b like I did above.
Why are you unsure about the first one ? 
Algebra  mysterychicken, Friday, May 6, 2011 at 5:19pm
Thanks; are the other 2 correct?
MC