Question

equaçao de 2 grau 5 (x² - 1) = 4 (x² + 1)

Answer 1

5 ( x²-1)=4 ( x²+1)
5 x²-5=4 x²+4
5 x²-4 x²-5-4=0
x²-9=0
x²=9
x=3