52000=57000*((1-(2/3)*(d/0.313))/(1-(2/3)*(d/0.313)/ $(1+0.8( $l^{2}$/(24*0.313)))^{0.5}$ ))
You asked:
Investigate the equation: \(52000 = 57000 \cdot \frac{1 - \frac{2}{3} \cdot \frac{d}{0.313}}{1 - \frac{\frac{2}{3} \cdot \frac{d}{0.313}}{{\left( 1 + 0.8 \cdot \frac{{l}^{2}}{24 \cdot 0.313} \right)}^{0.5}}}\).