Решите уравнениях^4-7х^2+12=0х^4-11х^2+18=0

X^4 - 7X^2 + 12 = 0  ---------------------- X^2 = A ( A > 0 )  A^2 - 7A + 12 = 0 D = 49 - 48 = 1 ; √ D = 1  A1 = ( 7 + 1 ) : 2 = 4  A2 = 6 : 2 = 3  ---------------- X^2 = A  ----------- X^2 = 4  X1 = 2  X2 = ( - 2 )  ---------- X^2 = 3  X3 = √ 3  X4 = - √ 3 =========== Уравнение 2  X^4 - 11X^2 + 18 = 0 --------- X^2 = A ( A > 0 ) A^2 - 11A + 18 = 0 D = 121 - 72 = 49 ; √ D = 7 A1 = ( 11 + 7) : 2 = 9  A2 = 4 : 2 = 2  ----------- X1 = 3 X2 = - 3  X3 = √ 2 X4 = - √ 2