Question

Ok I was wondering if you could check these 3 problems please. I am suppose to set these equations equal but I am not sure if did them right. I think I accidently solved these systems as substitutions. The answers are suppose to be in coordinate pairs.


1) x - y = 11
-3x + y = -21
I got (5,-16)

2) 5x - 4y = 17
-10x + 4y = -42
I got (5,3)

3) x + 3y = -1
3x + 3y = 15
I got (4,1)

Please check if i did it correctly please. thank you

Answer 1

Check your solutions with both equations. If your solutions don't fit both, then your answers need to be reworked. For example, using the solution you have for 1):

x = 5
y = -16

5 - (-16) = 11 -->false
-3(5) - 16 = -21 -->false

Solution for this system should be (5,-6).

5 - (-6) = 11 -->true
-3(5) - 6 = -21 -->true

Try the others again.