Question

X ao quadrado-4x-5=0

Answer 1

x² - 4x - 5 = 0

A= 1

B= - 4

C= - 5

∆= b² - 4ac

∆= ( - 4)² - 4 • 1 • ( - 5)

∆= 16 + 20

∆= 36

x= - b ± √∆ /2a

x= - ( - 4) ± √36/2 • 1

x= 4 ± 6/2

x'= 4 + 6/2 = 10/2 = 5

x''= 4 - 6/2 = - 2/2 = - 1

S= ( - 1 , 5)