2.diketahui persamaan 2ײ – 4× – 2 = 0
3.selesaikan persamaan kuadrat x² + 10× + 20 =0
1.tentukan Hp dari persamaan kuadrat x² + 6× – 14 = 0
Jawaban:
saya coba menjawab pertanyaan tersebut, kalau salah mohon dimaafkan
Penjelasan dengan langkah-langkah:
1. x² + 6x – 14 = 0
a= 1 b = 6. c = -14
-b ± √ ( b² – 4.a.c)
______________ = 0
2a
-6 ± √ ( 6² – 4 . 1 . -14 )
_________________ = 0
2.1
-6 ± √ ( 36 + 56)
_____________ = 0
2
-6 ± √ 92
________ = 0
2
-3 ± 1/2√92 =0
x1 = -3 + 1/2√92 atau
x2 = -3 – 1/2√92
Hp = { -3 + 1/2√92 , -3 – 1/2√92 }
2. 2x² – 4x – 2 = 0
( 2x – 2) ( 2x – 2 )
______________ = 0
2
( x – 1 ) ( x – 1 ) = 0
x – 1 = 0 atau x – 1 = 0
x = 1. x = 1
Hp = { 1 }
3. x² + 10x + 20 = 0
a = 1. b = 10 c = 20
-b ± √ ( b² – 4 . a . c )
________________ = 0
2.a
-10 ± √ ( 10² – 4 . 1 . 20 )
___________________= 0
2 . 1
-10 ± √ ( 100 – 80 )
______________ = 0
2
-10 ± √ 20
_________ = 0
2
-5 ± 1/2√20 = 0
x1 = -5 + 1/2√20 atau
x2 = -5 – 1/2√20
Hp = { -5 + 1/2√20 , -5 – 1/2√20 }