Solving linear equations simultaneously. Example:
4x-2y=85
2x+4y=136
Hi guys,
I am having a bit of trouble with solving linear equations and I can't seem to understand the explanations as well, considering that Math is my most least favored subject. Could you guys please help me?
Thanks,
+9481 4x – 2y = 85
2x + 4y = 136
On these, we can use the "elimination" method, where we line the two given equations up and add straight down. We could do that right now..but it won't yield a useful equation. We want one of the variables to go away when we add straight down. So let's multiply the top equation through by 2.
2(4x – 2y) = 2(85)
8x – 4y = 170
Now line this up with the second equation given and add straight down.
8x – 4y = 170
+ 2x + 4y = 136
10x + 0y = 306
10x = 306
x = 306/10
x = 30.6
Now we have found what x is!
Use this new found value for x in either equation to find what y is.
4(30.6) - 2y = 85
122.4 - 2y = 85
-2y = 85 - 122.4
-2y = -37.4
y = -37.4/-2
y = 18.7
