1/2 I guess I don't think you typed in the question correctly. Not trying to be mean.
2x+38=180
2x=142 (or x+x=142 from which 2x=142)
x=71
The unknown angles are each 71
You know this answer is logical as, since two sides are 21 it hints that we are looking at an equilateral triangle, which means two of its angles will be the same
Minus
The quadratic equation is
( -b+-SQRT(b^2 - 4ac) )/2a
Because y varies inversely as x, instead of directly, you will need to multiply x by a fractional number (or divide x) in order to find y.
When x=8, y=4. Therefore, to find y, you need the "equation" y=(1/2)(x) or y=x/2.
So, when x=2, y=(1/2)(2) or y=2/2.
And so, y=1
Hope this helps!