Answer:

3.) x²-2x-3=0

the answer of number three is 5 and -3

formula;

x= –b ± √b² - 4ac

2a

x= –(-2) ± √(-2)² – 4(1)(-3)

2(1)

x= 2 ± √4 - 4(-3)

2

x= 2 ± √4 + 12

2

x= 2 ± √16

2

x= 2 ± 8

2

x¹= 2 + 8 = 10 = 5

2 2

x2= 2 - 8 = 6 = -3

2 2