Toán Lớp 6: (2x+1)^3=-125 (X+2)^2=9.

Question

Toán Lớp 6:  (2x+1)^3=-125                       (X+2)^2=9.

hauthanhyen98 · Answer

a)  (2x+1)^3=-125                                      b) (X+2)^2=9         (2x+1)^3= (-5)^3                                    &rArr; (X+2)^2= 3^2     &rArr;  2x+ 1= -5                                              &rArr;    X+2     = 3     &rArr;  2x      = -5 -   1                                          &rArr; X          = 3-2     &rArr;  2x      = -6                                                &rArr; X          = 1     &rArr;    x      = -6 &divide;2      &rArr;    x       = -3

minhhaanh · Answer

$ text{$(2x + 1)^{3}$ = -125}$   $ text{$(2x + 1)^{3}$ = (-5)&sup3;}$   $ text{&rarr;2x + 1 = -5 }$   $ text{&rarr;2x        = (-5) - 1 }$   $ text{&rarr;2x        = -6 }$   $ text{&rarr;  x        = (-6) : 2 }$   $ text{&rarr;  x        = -3 }$   $ text{Vậy x = -3 }$   ___________________________    (x+2)&sup2;=9      $ text{(x+2)&sup2;=3&sup2; }$     $ text{&rarr;x+2 = 3 }$     $ text{&rarr;x      = 3 - 2 }$ $ text{&rarr;x      = 1 }$     $ text{ Vậy x = 1 }$     $ text{#bich2k9❤}$