Date: Tue, 1 Aug 2000 15:55:57 EDT

please help me with this homework question. 5/x + 6/y= 19/6 3/x + 4/y =2
hint: let a = 1/x and b = 1/y substitute these expressions into the system to find a and b. Then find x and y.

This is a question I answered wrong on a test: solve the given system for x, y, and z. Express your solutions in terms of a, b, and c.

x+y=a
y+z=b
x+z=c

Using the hint the equations become

I would multiply the first equation by 5 and the second equation by 3 so that in both cases the coefficient of a is 15. Subtract the two equations and solve for b and hence y which is 1/b.

For the second problem, subtract the first two equations so the left side is x-z. Then add this equation to the third equation so the left side becomes 2x. Finally divide both sides by 2 to get x=...

In a similar way solve for y and z.