Answer:
x =
is a solution
Explanation:
(x² - 7)² + 2x² - 14 = 0 ← factor out 2 from last 2 terms
(x² - 7)² + 2(x² - 7) = 0 ← factor out (x² - 7) from each term
(x² - 7)(x² - 7 + 2) = 0
(x² - 7)(x² - 5) = 0
equate each factor to zero and solve for x
x² - 7 = 0 ( add 7 to both sides )
x² = 7 ( take square root of both sides )
x = ±

x² - 5 = 0 ( add 5 to both sides )
x² = 5 ( take square root of both sides )
x = ±

solutions are x = -
,
, -
,
