if the area of a shape and another shape is same the area of one shape is 3x and the other is 250 minus xsquared what is x

3x  = 250 - x^2      add x^2 to both sides...subtract 250 from both sides

x^2 + 3x - 250   = 0      using the quadratic formula  and rejecting the negative value for x,  x  ≈ 14.382