Answer:
None of the options is correct
Step-by-step explanation:
It is important to know that he expression a < x < b means that x is greater than a and less than b. So, for finding the correct value let's analyse each option.
A. 4 < 50 < 5
50 is greater than 4 but it is not less than 5, so, option A is incorrect.
B. 7 < 50 < 8
50 is greater than 7 but it is not less than 8, so, option B is incorrect.
C. 8 < 50 < 9
50 is greater than 8 but it is not less than 9, so, option C is incorrect.
D. 10 < 50 < 11
50 is greater than 10 but it is not less than 11, so, option D is incorrect.
Thus, none of the options is correct.
<span><span> <span>Akar akar persamaan kuadrat 2x² - 3x -1 = 0 adalah x1 dan x2. Persamaan kuadrat baru yang akar akarnya satu lebih kecil dari dua kali akar akar persamaan kuadrat di atas adalah ........</span></span><span><span><span>A.x² - x - 4 = 0</span><span>B.x² + 5x - 4 = 0</span><span>C.x² - x + 4 = 0</span></span><span><span>D.x² + x + 4 = 0</span><span>E.x² - 5x - 4 = 0</span></span></span><span>Jawaban : A
Penyelesaian :
Akar-akar persamaan lama : x1 dan x2
Akar-akar persamaan baru : xA dan xB
xA = 2x1 - 1
xB = 2x2 - 1
xA + xB = (2x1 - 1) + (2x2 - 1)
= 2 (x1 + x2) - 2
= 2 () - 2
= 3 - 2
xA + xB = 1
xA . xB = (2x1 - 1) (2x2 - 1)
= 4 x1.x2 - 2(x1 + x2) + 1
= 4.(-) - 2() + 1
= -2 - 3 + 1
xA . xB = -4
Jadi persamaan kuadrat baru : x² - (xA + xB)x + xA . xB = 0
x² - x - 4 = 0
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