tìm x biết a) 2,5x+3/4=3,5x b) ( 8/7 -5/3 )*7/2x+6/5*15/7 = 2/7 x c) 08/09/2021 Bởi Adalynn tìm x biết a) 2,5x+3/4=3,5x b) ( 8/7 -5/3 )*7/2x+6/5*15/7 = 2/7 x c)
a) 2,5x + 3/4 = 3,5x 3/4 = 3,5x – 2,5x 3/4 = x ⇒ x =3/4 b) ( 8/7 -5/3 ) . 7/2x + 6/5 . 15/7 = 2/7x -11/21 . 7/2x + 18/7 = 2/7x – 11/6x + 18/7 = 2/7x 18/7 = 2/7x + 11/6x 18/7 = 89/42x x = 18/7 : 89/42 x = 108/89 Bình luận
Đáp án: Giải thích các bước giải: a) 2,5x +3/4 =3,5x ⇔ 3/4 = 3,5x – 2,5x ⇔x=3/4 b) (8/7 – 5/3).7/2 .x +6/5 . 15/7 = 2/7 . x -11/21 . 7/2 . x +18/7 = 2/7 . x -11/6 .x +18/7 = 2/7 .x 2/7 .x+ 11/6. x =18/7 89/42 . x = 18/7 x = 108/89 Bình luận
a) 2,5x + 3/4 = 3,5x
3/4 = 3,5x – 2,5x
3/4 = x
⇒ x =3/4
b) ( 8/7 -5/3 ) . 7/2x + 6/5 . 15/7 = 2/7x
-11/21 . 7/2x + 18/7 = 2/7x
– 11/6x + 18/7 = 2/7x
18/7 = 2/7x + 11/6x
18/7 = 89/42x
x = 18/7 : 89/42
x = 108/89
Đáp án:
Giải thích các bước giải:
a) 2,5x +3/4 =3,5x
⇔ 3/4 = 3,5x – 2,5x
⇔x=3/4
b) (8/7 – 5/3).7/2 .x +6/5 . 15/7 = 2/7 . x
-11/21 . 7/2 . x +18/7 = 2/7 . x
-11/6 .x +18/7 = 2/7 .x
2/7 .x+ 11/6. x =18/7
89/42 . x = 18/7
x = 108/89