Question

3 questões

1 - √x+1 = 2
2 - ³vx-2 = 1
3 - √x-1 = x-7

Answer 1

√x+1 = 2 
- √x = 2 -1
- √x = 1
√x = -1
x = -1² 
x = 1
 
³√x - 2 = 1
∛x = 1 +2
∛x = 3
x = 3³
x = 27

√x -1 = x-7
√x = x - 7 +1
√x = x -6
x = (x-6)²
x = x² -12x + 36.
x² - 12x + 36 -x = 0
x² - 13x + 36 = 0

bhaskara
b² -4ac
169 - 4.1.36
169 - 144
Δ=25

-b +/- √Δ / 2a 
-(-13) +/- √25 / 2.1
13 +/- 5 / 2

x1 = 13+5/2 = 18/2 = 9
x2 = 13-5/2 =8/2 = 4