Question

sqrt((3x+1))+sqrt((x-1))=6

Answer 1

Oi Biih

√(3x + 1) + √(x - 1) = 6 

3x + 1 + x - 1 + 2*√(3x + 1)√(x - 1) = 36 

2*√(3x + 1)√(x - 1) = 36 - 4x

√(3x + 1)√(x - 1) = 18 - 2x

(3x + 1)*(x - 1) = 4x² - 72x + 324 

3x² - 2x - 1 = 4x² - 72x + 324 

x² - 70x + 325 = 0 


delta
d² = 70² - 4*325 = 3600
d = 60

x1 = (70 + 60)/2 = 65 (não serve)
x2 = (70 - 60)/2 = 5