steps for (3x+3)^1/2-1=x find x?
回答 (3)
2017-02-24 3:59 pm
✔ 最佳答案
[(3x + 3)^1/2] - 1 = x[(3x + 3)^1/2] = x + 1
[(3x + 3)^1/2]^2 = (x + 1)^2
3x + 3 = x² + 2x + 1
x² - x - 2 = 0
(x - 2)(x + 1) = 0
x = 2 or x = -1
2017-02-24 4:20 pm
(3x + 3)^(1/2) - 1 = x
(3x + 3)^(1/2) = x + 1
[(3x + 3)^(1/2)]² = (x + 1)²
3x + 3 = x² + 2x + 1
x² - x = 2
x² - x + (1/2)² = 2 + (1/2)²
x² - x + (1/2)² = 9/4
[x - (1/2)]² = (± 3/2)²
x - (1/2) = ± 3/2
x = (1/2) ± (3/2)
x = (1 ± 3)/2
x = (1 - 3)/2 = - 1
x = (1 + 3)/2 = 2
(3x + 3)^(1/2) = x + 1
[(3x + 3)^(1/2)]² = (x + 1)²
3x + 3 = x² + 2x + 1
x² - x = 2
x² - x + (1/2)² = 2 + (1/2)²
x² - x + (1/2)² = 9/4
[x - (1/2)]² = (± 3/2)²
x - (1/2) = ± 3/2
x = (1/2) ± (3/2)
x = (1 ± 3)/2
x = (1 - 3)/2 = - 1
x = (1 + 3)/2 = 2
2017-02-24 3:57 pm
2 or -1
收錄日期: 2021-04-18 16:02:09
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