Question

1/5x+y=2/5
1/0x+1/3y=1/2

Answer 1

Best to enclose those fractions in parentheses:

(1/5)x + y = (2/5).

Otherwise, how would your reader know you didn't mean 1 / (5x) ?

Please note: Your 1/0x involves division by zero and thus is not defined. Make certain you've copied down the problem correctly.

If you present the following, instead, you can solve the system:

(1/5)x + y = (2/5).
x + (1/3)y = (1/2)

Hint: Determine what the LCD (lowest common denominator) is. Multiply both equations by this LCD, to remove all fractions from the problem.

Answer 2

a)
|x + y = 5
|2x - y = 7;
b)
|2x + y = 5
|x - y = 2
c)
|3x + y = 6
|4x - 3y = -5
d)
|1/(x - 1) = y - 3
|x - y = -2
e)
|(9x + 4y)/3 - (5x - 11)/2 = 13 - y
|13x - 7y = -8
Answer: c and e has solution (1; 3)