Question

in triangle abc 30a+6b=5c . determine angle a ,angle b ,angle c.

Answer 1

given 30a+6b=5c  5 * 6 = 30, so 
a = x
b = 5y

5c = 30x + 30y
c = 6(x + y)
c = 6x + 6y
for x, y > 0

A triangle is not possible.

Answer 2

It is not possible as c = 6x + 6y and hence triangle is not possible