Question

x^2+1=5 (determinati solutia ecuatilor)
3x^2-4=23

Answer 1

~x² + 1 = 5

x² + 1 - 5 = 5 - 5
(x+2) (x-2) = 0
x² - x•2 + 2x - 4
x = 2
S = {±2}

~3x² - 4 = 23

3x² - 4 - 23 = 23 - 23
(x+3) (x-3) = 0
x² - x•3 + 3x - 9
x = 3
S = {±3}.