Question

Решите плииииз:* x+корень из{x} -20=0

Answer 1

$x+\sqrt{x}-20=0\\\\ t=\sqrt{x}\\\\ t^{2}+t-20=0\\ D=b^{2}-4ac=1^{2}-4\cdot1\cdot(-20)=81\\\\ x_{1,2}=\frac{-b+/-\sqrt{D}}{2a}\\\\ x_{1}=\frac{-1+9}{2}=4\\\\ x_{2}=\frac{-1-9}{2}=-5$