Dengan menggunakan rumus abc. Tentukan akar-akar dari persamaan kuadrat dibawah ini!

Jawaban:

1. (x +6)(x-2)

2. (x-6)(x+2)

3. (x+5)(x+1)

4. (x-1)(x-5)

5. (x-1)(x-7)

Penjelasan dengan langkah-langkah:

1.

a = 1

b = 4

c = -12

4 ±√4² – 4(1)(–12)

2(1)

= 4 ± √16 + 48

2

=

4 ± √64

2

= 4 ± 8

2

x1 = 2 + 4 = 6

X2 = 2 -4 = -2

no 2 sama tinggal diganti – nya

x1 = – 2 + 4 = 2

X2 = -2 -4 = -6

3. dan 4 sama unt pengerjaan nya tinggal diganti + – nya

no 3

a = 1

b = 6

c = 5

no. 4

a = 1

b = -6

c = 5

6 ±√6²–4(1)(5)

2(1)

=

6 ± √36 –20

2

=

6 ±√ 16

2

=

6 ± 4

2

X1 = 3 + 2 = 5

X2 = 3 – 2 = 1

no 4

X1 = -3 + 2 = -1

X2 = -3 -2 = -5

5.

a = 1

b = -8

c = 7

–8 √8² – 4(1)(7)

2(1)

=

–8 ± √64 – 28

2

=

–8 ±√36

2

=

–8 ± 6

2

X1 = -4 + 3 = -1

X2 = -4 – 3 = -7

semoga membantu