Solve the equation: 38x²-9x-5=0?
回答 (9)
2008-02-22 5:57 pm
✔ 最佳答案
Factor first:(19x + 5) * (2x - 1) = 0
Now just read off the roots
x = {-5/19, 1/2}
2008-02-23 7:02 am
(19x + 5)(2x - 1) = 0
x = - 5 / 19 , x = 1 / 2
x = - 5 / 19 , x = 1 / 2
2008-02-23 2:00 am
the answer is (19x+5)(2x-1)
then
19x+5=0 2x-1=0
19x=-5 2x=1
x=-5/19 x=1/2
then
19x+5=0 2x-1=0
19x=-5 2x=1
x=-5/19 x=1/2
2008-02-23 1:59 am
Not even going to try to factor that - I'll go right to the quadratic equation:
x = [ -b ± â(b² - 4ac)] / 2a
x = [ -(-9) ± â((-9)² - 4(38)(-5))] / 2(38)
x = [ 9 ± â(81 + 760)] / 76
x = [ 9 ± â(841)] / 76
x = [ 9 ± 29 ] / 76
x = (9 + 29) / 76, (9 - 29) / 76
x = 38 / 76, -20 / 76
x = 1/2, -5/19
x = [ -b ± â(b² - 4ac)] / 2a
x = [ -(-9) ± â((-9)² - 4(38)(-5))] / 2(38)
x = [ 9 ± â(81 + 760)] / 76
x = [ 9 ± â(841)] / 76
x = [ 9 ± 29 ] / 76
x = (9 + 29) / 76, (9 - 29) / 76
x = 38 / 76, -20 / 76
x = 1/2, -5/19
2008-02-23 1:59 am
38x^2 - 9x - 5 = 0
(2x - 1)(19x + 5) = 0
2x - 1 = 0
2x = 1
x = 1/2
19x + 5 = 0
19x = -5
x = -5/19
â´ x = 1/2 , x = -5/19
(2x - 1)(19x + 5) = 0
2x - 1 = 0
2x = 1
x = 1/2
19x + 5 = 0
19x = -5
x = -5/19
â´ x = 1/2 , x = -5/19
2008-02-23 1:57 am
It factors (19x +5 )(2x -1) =0
x = -5/19, 1/2
x = -5/19, 1/2
2008-02-23 1:57 am
(19x + 5)(2x - 1) = 0
19x + 5 = 0 or 2x - 1=0
19x=-5 or 2x=1
x = -5/19, x = 1/2
19x + 5 = 0 or 2x - 1=0
19x=-5 or 2x=1
x = -5/19, x = 1/2
2008-02-23 1:56 am
(19x+5)(2x-1)=0
x=-5/19, 1/2
x=-5/19, 1/2
2008-02-23 1:59 am
factors of 38: (1, 2, 19, 38)
factors of 5: (1, 5)
(19x + 5) (2x - 1) = 0
19x + 5 = 0 /// and /// 2x-1 = 0
19x+5=0
19x=-5
x= -5/19
2x-1=0
2x=1
x=1/2
x= -5/19 , 1/2
factors of 5: (1, 5)
(19x + 5) (2x - 1) = 0
19x + 5 = 0 /// and /// 2x-1 = 0
19x+5=0
19x=-5
x= -5/19
2x-1=0
2x=1
x=1/2
x= -5/19 , 1/2
收錄日期: 2021-05-01 10:07:20
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