Step-by-step explanation:
[tex]\sqrt{ x^{2}-10x+25}+25+12\sqrt{x} =15\sqrt{x} \\ \\ \therefore \: \sqrt{ x^{2}-10x+ {5}^{2} }+25 =15\sqrt{x} - 12\sqrt{x}\\ \\ \therefore \: \sqrt{( x - 5)^{2}}+25 =3\sqrt{x} \\ \\ \therefore \: x - 5+ 25 = 3 \sqrt{x} \\ \\ \therefore \: x + 20 = 3 \sqrt{x} \\ \\ squaring \: both \: sides \\ (x + 20)^{2} = ( {3 \sqrt{x} })^{2} \\ \therefore \: {x}^{2} + 40x + 400 = 9x \\ \therefore \: {x}^{2} + 40x + 400 - 9x = 0 \\ \therefore \: {x}^{2} + 31x + 400 = 0 \\ [/tex]