posted by annonymous .
if a=3x+2y and b=5x-4y, find x and y in terms of a and b
What I did:
11x dvided by x = 11
...that isn't the correct answer. The correct answer (according to text book) is
I'm puzzled on how to do this with all the letters. I also don't know how to find out y. I think I did a bit of figuring for x right, right?
you made an error in the initial addition.
2a = 6x + 4y
b = 5x - 4y
2a + b = 11x
x = (2a+b)/11 or 2a/11 + b/11 , which is the given answer
now plug the x back into the first equation:
5x - 4y = b
5(2a+b)/11 - 4y = b
5(2a + b) - 44y = 11b
10a + 5b - 44y = 11b
-44y = -10a + 6b
y = (-10a + 6b)/-44
= (5a - 3b)/22 , which is the same as the given y