Question

Если $x\sqrt{x} -9\sqrt{x} =8$ то найдите $x-\sqrt{x}$

Answer 1

Ответ:

Объяснение:

√х=t

t²×t-9t=8

t³-9t=8

t³-9t-8=0

t³-t-8t-8=0

t(t²-1)-8(t+1)=0

t(t-1)(t+1)-8(t+1)=0

(t+1)×(((t(t-1))-8))=0

t²-t-8=0

t(1)=1+√33 /2 t(2)=1-√33,/2

√x=1+√33/2

x=17+√33/2

17/2+√33/2-(1/2+√33/2)= 17+√33-1-√33/2= 16/2=8