METHOD:,We have X^3+Y^3=-56.Let this be Equation (1) We have X+Y=2.Let this be Equation (2). (X+Y)^3=X^3+Y^3+3XY(X+Y).since X+Y=2. We have 8=-56+6XY.@XY=32/3. From this XY=32/3. And X+H=2. You get quadratic Equation. Where a=3 b=-2 and c=32. Roots of the equation formula applied to get X value. Substituting this you get Y also. Then you can get X-Y.
METHOD:,We have X^3+Y^3=-56.Let this be Equation (1)
We have X+Y=2.Let this be Equation (2).
(X+Y)^3=X^3+Y^3+3XY(X+Y).since X+Y=2. We have 8=-56+6XY.@XY=32/3. From this XY=32/3. And X+H=2. You get quadratic Equation. Where a=3 b=-2 and c=32. Roots of the equation formula applied to get X value. Substituting this you get Y also. Then you can get X-Y.
Not H but Y