1. The document provides solutions to several quadratic equations using factoring, completing the square, and the quadratic formula. 2. The equations are solved step-by-step showing the work. Common solutions included factoring the equation into two binomial factors and setting each factor equal to zero, or using the quadratic formula. 3. Additional context is provided about solving quadratic equations with different methods like completing the square or using the standard formula.

1. 1. Selesaikan persamaan kuadrat di bawah dengan cara memfaktorkan
a. x2 + 5x - 50 = 0
b. x2 + 3x = 0
c. x2 - 4 = 0
d. 2x2 + 3x + 1 = 0
e. 3x2 + 5x - 2 = 0
Jawab:
a.
x2 + 5x - 50 = 0
x2 + 10x – 5x – 50 = 0
(x2 + 10x) – (5x – 50) = 0
x(x + 10) – 5(x + 10) = 0
(x – 5) (x + 10) = 0
x = 5 atau x = -10
b. x2 + 3x = 0
x2 + 2x + x = 0
(x2 + 2x) + x = 0
x(x + 3) = 0
x = -3
c. x2 - 4 = 0
x2 + 2x – 2x – 4 = 0
(x2 +2x) – (2x – 4) = 0
x(x + 2) – 2(x + 2) = 0
(x – 2) (x + 2) = 0
x = 2 atau x = -2
d. 2x2 + 3x + 1 = 0
2x2 + 2x + x + 1 = 0
(2x2 + 2x) + (x + 1) = 0
2x(x +1) + (x + 1) = 0
(2x + 1) (x +1) = 0
x = - atau x = -1

2. e. 3x2 + 5x - 2 = 0
3x2 – x + 6x -2 = 0
(3x2 – x) + (6x – 2) = 0
x(3x – x) + 2(3x –1) = 0
(x + 2) (3x – 1) = 0
x = -2 atau x =
2. Selesaikan persamaan kuadrat berikut ini dengan melengkapkan kuadrat sempurna
a. x2 + 5x +4 = 0
b. 2x2 – 14x + 12 = 0
Jawab:
a. x2 + 5x +4 = 0
x2 + 5x +4 – 4 = 0 -4
x2 + 5x + (
)2 = (
)2 – 4
(x + 5)2 = ( 5)2 – 4
2
(x + 5) = ±
-4
2
X =- 5±
2
= -2,5 ±
-4
-4
= -2,5±
= -2,5 ±
= -2,5± 1,5
x = -2,5 + 1,5 = -1, atau
x = -2,5 – 1,5 = -4
b. 2x2 – 14x + 12 = 0
X2 – 7x + 6 = 0
X2 – 7x + 6 – 6 = 0 – 6
X2 – 7x + ( 7)2 = ( .7)2 – 6
(x + 7)2 = ( 7)2 – 6
(x + 7) = ±
X=- 7±
2
-6
2
-6

3. 2
= -3,5 ±
-6
= -3,5±
= -3,5 ±
= -3,5± 2,5
X = -3,5 + 2,5 = -1 atau
X = -3,5 – 2,5 = -6
3. Selesaikan persamaan kuadrat berikut ini dengan rumus abc
a. x2 - 15x + 30 = 0
Jawab:
X1,2
b. x2+ 8x - 20 = 0
Jawab:
X1,2
X1
= =2
X2 =
=
= -10

4. c. x 2 + 3x = 0
Jawab:
X1,2
X1
X2 =
=
= -3
4. Tentukan p agar persamaan kuadrat (p+3)x2 + 3x - 4 = 0 mempunyai dua akar sama.
Jawab:
(p+3)x2 + 3x - 4 = 0
D = b2 – 4ac
= 32 – 4(p+3). – 4
= 9 – 4p – 12. – 4
= 9+ 16p + 48
-16p = 9 + 48
-16p = 57
P=

5. NAMA KELOMPOK B :
1. DWI NURUL KHOTIMAH
2. NI KADEK INTAN SUARINI
3. NI MADE DEWI DAMAYANTI
4. NI PUTU DIAN INTAN GINANTI
(06)
(20)
(24)
(29)