Question

Rezolvati ecuatia: y^1/4 + y^1/2 = 90

Answer 1

Notam $y^{ \frac{1}{4} }=z,z\ \textgreater \ 0, y^{ \frac{1}{2} }=z^2,obtinem,ec.z^2+z-90=0,cu,radacina,z=9$, si -10 care nu e acteptata. Deci y^$\frac{1}{4}$=9 ridicand egalitatea la puterea a 4-a obtinem  $y= 9^{4}$