Find ddx[5x]\frac{d}{dx} [\sqrt{5x}]dxd[5x].
125x\frac{1}{2\sqrt{5x}}25x1
525x\frac{5}{2\sqrt{5x}}25x5
15x\frac{1}{\sqrt{5x}}5x1
52x\frac{5}{2} \sqrt{x}25x