Tìm x , biết a) 17/15.x=14/45 b) 72:x= 36/19 c) 2/5.x-1/4=-3/20 d) 2/3+4/7:x=-1/5 13/11/2021 Bởi Eloise Tìm x , biết a) 17/15.x=14/45 b) 72:x= 36/19 c) 2/5.x-1/4=-3/20 d) 2/3+4/7:x=-1/5
a) 17/15.x=14/45 ⇔ x = 14/45 : 17/15 ⇔ x = 14/51 b) 72:x= 36/19 ⇔ x = 72 : 36/19 ⇔ x = 38 c) 2/5.x-1/4=-3/20 ⇔ 2/5.x =-3/20 + 1/4 ⇔ 2/5.x = 1/10 ⇔ x = 1/10 : 2/5 ⇔ x = 1/4 d) 2/3+4/7:x=-1/5 ⇔ 4/7: x = -1/5 – 2/3 ⇔ 4/7: x = -13/15 ⇔ x = 4/7 : -13/15 ⇔ x = – 60/91 Bình luận
a) 17/15 . x = 14/45 x = 14/45 : 17/15 x = 14/15 . 15/17 x = 14/1 . 1/17 x = 14/17 b) 72 : x = 36/19 x = 72 : 36/19 x = 72/1 . 19/36 x = 2/1 . 19/1 x = 38 c) 2/5 . x – 1/4 = -3/20 2/5 . x = -3/20 + 1/4 2/5 . x = -3/20 + 5/20 2/5 . x = 1/10 x = 1/10 : 2/5 x = 1/10 . 5/2 x = 1/2 . 1/2 x = 1/4 d) 2/3 + 4/7 : x = -1/5 4/7 : x = -1/5 – 2/3 4/7 : x = -3/15 – 10/15 4/7 : x = -3/15 + -10/15 4/7 : x = -13/15 x = 4/7 : -13/15 x = 4/7 . 15/-13 x = 60/-91 Bình luận
a) 17/15.x=14/45
⇔ x = 14/45 : 17/15
⇔ x = 14/51
b) 72:x= 36/19
⇔ x = 72 : 36/19
⇔ x = 38
c) 2/5.x-1/4=-3/20
⇔ 2/5.x =-3/20 + 1/4
⇔ 2/5.x = 1/10
⇔ x = 1/10 : 2/5
⇔ x = 1/4
d) 2/3+4/7:x=-1/5
⇔ 4/7: x = -1/5 – 2/3
⇔ 4/7: x = -13/15
⇔ x = 4/7 : -13/15
⇔ x = – 60/91
a) 17/15 . x = 14/45
x = 14/45 : 17/15
x = 14/15 . 15/17
x = 14/1 . 1/17
x = 14/17
b) 72 : x = 36/19
x = 72 : 36/19
x = 72/1 . 19/36
x = 2/1 . 19/1
x = 38
c) 2/5 . x – 1/4 = -3/20
2/5 . x = -3/20 + 1/4
2/5 . x = -3/20 + 5/20
2/5 . x = 1/10
x = 1/10 : 2/5
x = 1/10 . 5/2
x = 1/2 . 1/2
x = 1/4
d) 2/3 + 4/7 : x = -1/5
4/7 : x = -1/5 – 2/3
4/7 : x = -3/15 – 10/15
4/7 : x = -3/15 + -10/15
4/7 : x = -13/15
x = 4/7 : -13/15
x = 4/7 . 15/-13
x = 60/-91