x^4-9x^2+ 14
=(x^2 - 7)(x^2 - 2)
solve for x
x^2-2 = 0
x^2 = 2
x = +√ 2 = + 1.4142 and x = -√ 2 = - 1.4142
x^2-7 = 0
x^2 = 7
x = + √ 7 = +2.6458 and x = - √ 7 = - 2.6458
answer: 4 solutions
x = +√ 2 = + 1.4142
x = - √ 2 = - 1.4142
x = + √ 7 = +2.6458
x = - √ 7 = - 2.6458