Question

x elevado a 2- 4x+4=25​

Answer 1

x² - 4x + 4= 25

x² - 4x + 4 - 25 = 0

x² - 4x - 21 = 0

A= 1

B= - 4

C= - 21

∆= b² - 4ac

∆= ( - 4)² - 4 • 1 • ( - 21)

∆= 16 + 84

∆= 100

x= - b ± √∆/2a

x= - ( - 4) ± √100/2 • 1

x'= 4 + 10/2 = 14/2 = 7

x''= 4 - 10/2 = - 6/2 = - 3

S= ( - 3 , 7)