指數方程(easy)

2009-11-05 7:09 am
(please explain how to do them)

1. 4√x^3-500=0

2. 80x^-4/3-5=0

3.64x^3/2=27

回答 (1)

2009-11-05 7:56 am
✔ 最佳答案
1. 4√(x^3) - 500 = 0
4√(x^3) = 500
√(x^3) = 125
√(x^3) = 5^3
x^3 = (5^3)^2 = (5^2)^3
x^3 = 25^3
x = 25
2. 80x^(-4/3) - 5 = 0
80x^(-4/3) = 5
x^(-4/3) = 1/16
x^(4/3) = 16 = 2^4
[x^(4/3)]^3 = (2^4)^3
x^4 = (2^3)^4 = 8^4
x = 8
3. 64x^(3/2) = 27
(2^6)x^(3/2) = 3^3
[(2^6)x^(3/2)]^2 = [3^3]^2
2^12x^3 = 3^6
x^3 = 3^6 / 2^12 = 9^3 / 16^3
x = 9/16


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