Posted by mysterychicken on Friday, May 6, 2011 at 1:39pm.
Need help with these
40. The graph of the following system yields perpendicular lines:
x + 2y = 10
4y = 2x + 20
True or False?
42. If we multiply a 2 x 2 matrix with a 2 x 1 matrix, the product is a 2 x 1 matrix.
False?
Thanks
MC

Algebra  Jackie, Friday, May 6, 2011 at 2:27pm
41. False. If you solve both equations for "y", you will get the same line; which means they can not be perpendicular.
42. True. When you have two matrices multiplied together, (2 x 2)(2 x1). If the two inner numbers match, then your resulting matrix will be the two outer numbers. 
Algebra  mysterychicken, Friday, May 6, 2011 at 2:30pm
Thank you!
MC