Jawab:
(6.) (A) {-2, -3}
(7.) (D) = -14
(8.) = 8
(9.) (C) x = -5
(10) (A) = 3
Penjelasan:
Ax² + Bx + C = 0
p dan q akar-akar
p+q = -B/A, pq = C/A
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(6.) x² + 5x + 6 = 0
A = 1, B = 5, C = 6
p dan q akar-akar
p+q = -B/A, pq = C/A
p+q = -5/1, pq = 6/1
p+q = -5, pq = 6
p = -3, q = -2
{-2, -3} (opsi A)
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(7.) x² + 5x + c = 0
A = 1, B = 5, C = c
2 dan q akar-akar
2+q = -B/A, 2q = C/A
2+q = -5/1, 2q = c/1
2+q = -5, 2q = c
--> Carilah q
2+q = -5
q = -5-2
q = -7
--> Carilah c
2q = c
2(-7) = c
c = -14 (opsi D)
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(8.) x² - 5x + c = 0
A = 1, B = -5, C = c
-3 dan q akar-akarnya
q - 3 = -B/A, -3q = C/A
q - 3 = -(-5)/1, -3q = c/1
q - 3 = 5, -3q = c
--> cari q (penyelesaian)
q = 5+3
q = 8 (salah soal)
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(9.) x² + 2x + c = 0
A = 1, B = 2, C = c
3 dan q akar-akarnya
3 + q = -B/A, 3q = C/A
3 + q = -2/1, 3q = c/1
3 + q = -2, 3q = c
--> cari q (akar lain)
3 + q = -2
q = -2-3
q = -5
atau x = -5 (opsi C)
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(10) x² - 3x - 10 = 0
A = 1, B = -3, C = -10
Ditanya p+q
p+q = -B/A
p+q = -(-3)/1
p+q = 3 (opsi A)
(xcvi)
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