Question

resolver a equação biquadrada: x4 -13x² + 36 = 0

Answer 1

x⁴ -13x² + 36 = 0 => -13/36 = -4-9/-4×-9 ↓

(x² -4) . (x² -9)= 0

(x²=4) . (x²=9)

x= ±2. x=±3. <====©