Maths Question!!!!

Question

How to solve 1. x-開方x-1=1---------------------------係開方全個x-1
2. 開方3x-3+5=2x----------------------只是開方3x-3

1. x-√x-1=1
2. √3x-3+5=2x----------------------只是開方3x-3


yimching_ho，我並不是話你錯，but the book say the no.1 answer is 3 and no.2 answer is 4

Answer 1

√

x-√(x-1) = 1
x-1=√(x-1)
(x-1)² = [√(x-1)]²
x² - 2x + 1 = x -1
x² -3x + 2 = 0
(x-2)(x-1)=0
x=2 or x=1

√(x-3) + 5 = 2x
√(x-3) = 2x - 5
[√(x-3)]² = (2x-5)²
x-3 = 4x² - 20x + 25
4x² - 21x + 28 = 0
b² - 4ac = 21² - 4(4)(28) = -7
no real root, no solution to this question if complex is not accepted.
無實數解。

Answer 2

x-開方x-1=1
x(x-1)-x-1=1(x-1)
x2次方-x-x-1=x-1
x2次方-x=0
x2次方=x
x=1

for the second one, i cannot solve it, sorry....