The three angles of a triangle have angle a= x=2y degrees, angle b= 6x-5y degrees and angle c= 5x+3y degrees. Find x (in degrees).

x == 2y

y ==1/2x

[x + ( 6x - 5*1/2x) + (5x + 3*1/2x) ]==180, solve for x

11x == 180

x=180 / 11 == 16.364 degrees

I think that probably the second = sign in the first equation a = x = 2y should be a plus sign, i.e. it should be a = x + 2y.

Now the sum of the three angle is (x + 2y) + (6x - 5y) + (5x + 3y) = 12x.

That has to equal 180, so x = 180/12 = 15.