Question

Mostre que 8/5 é raiz da equação x^2 – 3,6x + 16/5 = 0

Answer 1

x²-36/10x+16/5=0
x²-18/5x+16/5=0
5x²-5*18/5x+5*16/5=5*0
5x²-18x+16=0


x=-(-18)+-raiz(-18)²-4*5*16/2*5
x=18+-raiz324-320/10
x=18+-raiz4/10
x=18+-2/10