tentukan himpunan penyelesaian persamaan nilai mutlak berikut 1. | 2× - 3 | = 6 2. | 3× - 1 | = 2 3. | × -6 | + | 3 + 2× | = 20 4. |× + 4 | + |× + 2 | = 12
Matematika
kharisa3
Pertanyaan
tentukan himpunan penyelesaian persamaan nilai mutlak berikut
1. | 2× - 3 | = 6
2. | 3× - 1 | = 2
3. | × -6 | + | 3 + 2× | = 20
4. |× + 4 | + |× + 2 | = 12
1. | 2× - 3 | = 6
2. | 3× - 1 | = 2
3. | × -6 | + | 3 + 2× | = 20
4. |× + 4 | + |× + 2 | = 12
1 Jawaban
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1. Jawaban AngelaJenia
1. 2x = 6+3
2x = 9
x = 9 : 2
x = 4,5
2. 3x = 2+1
3x = 3
x = 3 : 3
x = 1
3. (x - 6) + ( 3 + 2x) = 20
-------------^ x ^ & ^
hasilnya = x - 6 + 3 + 2x = 20
(kita cari mana suku yang sama?)
suku yang sama adalah - 6 dan 3 serta x dan 2x
Jadi = x + 2x = 3x
= -6 + 3 = -3
----------------------------
3x-3 = 20
3x = 20+3
3x = 23
x = 23 : 3
x = 7,66666 dibulatkan menjadi 7,7 .
4. ( x + 4 ) + ( x + 2) = 12
( caranya sama kayak nomor 3 )
x + 4 + x + 2 = 12
2x + 6 = 12
2x = 12 - 6
2x = 6
x = 6 : 2
x = 3