Question

1. x²+8x+12=0
2. 2x²+5x-3=0
3. 3x²-8x+4=0
4. 4x²-8x-5=0

selesaikan dengan rumus ABE​

Answer 1

Jawaban:

x² + 8x + 12 = 0

a = 1

b = 8

c = 12

x = -b ± √b² - 4ac

2a

x = -8 ± √8² - 4(1)(12)

2(1)

x = -8± √64 - 48

2

x = -8 ±√16

2

x = -8 ± 4

2

x 1 = -8 + 4

2

x1 = -4/2 = -2

x2 = -8-4

2

x2 = -12/2 = -6

2x² +5x -3 = 0

a = 2

b = 5

c = -3

x = -b ± √b² - 4ac

2a

x = -5 ± √5² - 4(2)(-3)

2(2)

x = -5± √25 +24

4

x = -5 ±√49

4

x = -5 ± 7

4

x 1 = -5 + 7

4

x1 = 2/4 = ½

x2 = -5-7

4

x2 = -12/4 = -3

3x² -8x + 4 =0

a = 3

b = -8

c = 4

x = -b ± √b² - 4ac

2a

x = -(-8) ± √(-8)² - 4(3)(4)

2(3)

x = 8± √64 - 48

6

x = 8 ±√16

6

x = 8 ± 4

6

x 1 = 8 + 4

6

x1 = 12/6 = 2

x2 = 8-4

6

x2 = 4/6 = ⅔

4x²-8x-5=0

a = 4

b = -8

c = -5

x = -b ± √b² - 4ac

2a

x = -(-8) ± √(-8)² - 4(4)(-5)

2(4)

x = 8± √64 + 80

8

x = 8 ±√144

8

x = 8 ± 12

8

x 1 = 8 + 12

8

x1 = 20/8 = 5/2

x2 = 8- 12

8

x2 = -4/8 = -½