Toán Lớp 6: Bài 1: tìm x E Z, sao cho: (x+3)^4=16 (3x-1)^5=32 37+3x=40 105-(135-7x):9=97 Mn giúp mik với

Question

Toán Lớp 6:  Bài 1: tìm x E Z, sao cho: (x+3)^4=16 (3x-1)^5=32 37+3x=40 105-(135-7x):9=97 Mn giúp mik với

ngocle44 · Answer

( x + 3 )^4 = 16     &hArr; x + 3 = &plusmn; 2     &hArr;  ( left[  begin{array}{l}x+3=2  x+3=-2 end{array}  right. )      &hArr;  ( left[  begin{array}{l}x=- 1  x=-5 end{array}  right. )      Vậy x = - 1 ; x = - 5     ( 3x - 1 )^5 = 32     &hArr; ( 3x - 1 )^5 = 2^5     &hArr; 3x - 1 = 2     &hArr; 3x = 2 + 1      &hArr; 3x = 3     &hArr; x = 3 : 3     &hArr; x = 1     Vậy x = 1     37 + 3x = 40     &hArr; 3x = 40 - 37     &hArr; 3x = 3     &hArr; x = 3 : 3     &hArr; x = 1     Vậy x = 1     105 - ( 135 - 7x ) : 9 = 97     &hArr; - ( 135 - 7x ) : 9 = 97 - 105     &hArr; - ( 135 - 7x ) : 9 = - 8     &hArr; - 135 + 7x  = - 8 . 9     &hArr; - 135 + 7x  = - 72     &hArr; 7x = - 72 + 135     &hArr; 7x = 63     &hArr; x = 63 : 7     &hArr; x = 9     Vậy x = 9

kimoanh34 · Answer

(x+3)^4=16   (x+3)^4=2^4    text{TH 1 :}                         text{TH 2 :}   x+3=2                                 x+3=-2   x=2-3                                  x=(-2)-3   x=-1                                    x=-5   &rArr; x &isin; { -1 ; -5 }   (3x-1)^5=32   (3x-1)^5=2^5   3x-1=2   3x=2+1   3x=3   x=3:3   x=1    text{Vậy x = 1}   37+3x=40   3x=40-37   3x=3   x=3:3   x=1    text{Vậy x = 1}   105-(135-7x):9=97   (135-7x):9=105-97   (135-7x):9=8   135-7x=8.9   135-7x=72   7x=135-72   7x=63   x=63:7   x=9    text{Vậy x = 9}    text{@Jinz}