Lê Anh Thư
Giới thiệu về bản thân
a) x = -4.-11/2
x = 22
b) (15 - x ).5 = ( x + 9 ).3
75 - 5x = x3 + 27
8x = 48
x = 6
Chu vi của mảnh vườn hình chữ nhật đó là:
( 5,5 + 3,75 ) . 2 = 18,5 ( m )
Số khóm hoa cần trồng là:
18,5 : 1/4 = 74 ( khóm hoa )
Đáp số: 74 khóm hoa.
a) 1/5 + 4/5 : x = 0,75
1/5 + 4/5 : x = 3/4
4/5 : x = 3/4 - 1/5
4/5 : x = 11/20
x = 4/5 : 11/20
x = 16/11
Vậy x = 16/11
b) x + 1/2 = 1 - x
( x . 2 ) + 1/2 = 1
( x . 2 ) = 1 - 1/2
x . 2 = 1/2
x = 1/2 : 2
x = 1/4
Vậy x = 1/4
a) 2/3 . 5/4 - 3/4 . 2/3
= 2/3 . ( 5/4 - 3/4 )
= 2/3 . 1/2
= 2/6 = 1/3
b) 2 . ( -3/2 )^2 - 7/2
= 2 . ( -3/4 ) - 7/2
= 2 . ( -17/4 )
= -17/2
c) -3/4 . 5( 3/13 ) - 0,75 . 36/13
= -3/4 . 68/13 - 3/4 . 36/13
= 3/4 . ( -68/13 - 36/13 )
= 3/4 . ( -8 )
= -6
a) ( 1/2 + 1,5 ) . x = 1/5
2 . x = 1/5
x = 1/5 : 2
x = 1/10
Vậy x = 1/10
b) [ -1(3/5) + x ] : 12/13 = 2(1/6)
( -8/5 + x ) = 13/6 . 12/13
( -8/5 + x ) = 2
x = 2 - (-8/5)
x = 18/5
Vậy x = 18/5
c) [ x : 2(1/3) ] . 1/7 = -3/8
( x : 7/3 ) = -3/8 : 1/7
( x : 7/3 ) = -21/8
x = -21/8 . 7/3
x = -49/8
Vậy x = -49/8
d) -4/7 . x + 7/5 = 1/8 : -1(2/3)
-4/7 . x + 7/5 = -3/40
-4/7 . x = -3/40 - 7/5
-4/7 . x = -59/40
x = -59/40 : -4/7
x = 413/160
Vậy x = 413/160
a) 1/2 - ( x + 1/3 ) = 5/6
x +1/3 = 1/2 - 5/6
x + 1/3 = -1/3
x = -1/3 - 1/3
x = -2/3
Vậy x = -2/3
b) ( 3/8 - 1/5 ) + ( 5/8 - x ) = 1/5
7/40 + ( 5/8 - x ) = 1/5
5/8 - x = 1/5 - 7/40
5/8 - x = 1/40
x = 5/8 - 1/40
x = 3/5
Vậy x = 3/5
a) -1,62 + 2/5 + x = 7
2/5 + x = 7 - ( -1,62 )
2/5 + x = 8,62
x = 8,62 - 2/5
x = 8,22
vậy x = 8,22
b) 4(2/5) - x = -1/5 + 1/2
23/5 - x = 3/10
x = 23/5 - 3/10
x = 43/10
Vậy x = 43/10
c) -4/7 - x = 3/5 - 2x
-x - 4/7 = -2x + 3/5
-x - 4/7 + 4/7 = -2x + 3/5 + 4/7
-x = -2x + 41/35
-x + 2x = -2x + 41/35 + 2x
x = 41/35
Vậy x = 41/35
d) 5/7 - 1/13 + 0,25 = 3(1/2) - x
5/7 - 1/13 + 1/4 = 7/2 - x
323/364 = 7/2 - x
x = 7/2 - 323/364
x = 951/364
Vậy x = 951/364
a) -1,62 + 2/5 + x = 7
2/5 + x = 7 - ( -1,62 )
2/5 + x = 8,62
x = 8,62 - 2/5
x = 8,22
vậy x = 8,22
b) 4(2/5) - x = -1/5 + 1/2
23/5 - x = 3/10
x = 23/5 - 3/10
x = 43/10
Vậy x = 43/10
c) -4/7 - x = 3/5 - 2x
-x - 4/7 = -2x + 3/5
-x - 4/7 + 4/7 = -2x + 3/5 + 4/7
-x = -2x + 41/35
-x + 2x = -2x + 41/35 + 2x
x = 41/35
Vậy x = 41/35
d) 5/7 - 1/13 + 0,25 = 3(1/2) - x
5/7 - 1/13 + 1/4 = 7/2 - x
323/364 = 7/2 - x
x = 7/2 - 323/364
x = 951/364
Vậy x = 951/364
a) -1,62 + 2/5 + x = 7
2/5 + x = 7 - ( -1,62 )
2/5 + x = 8,62
x = 8,62 - 2/5
x = 8,22
vậy x = 8,22
b) 4(2/5) - x = -1/5 + 1/2
23/5 - x = 3/10
x = 23/5 - 3/10
x = 43/10
Vậy x = 43/10
c) -4/7 - x = 3/5 - 2x
-x - 4/7 = -2x + 3/5
-x - 4/7 + 4/7 = -2x + 3/5 + 4/7
-x = -2x + 41/35
-x + 2x = -2x + 41/35 + 2x
x = 41/35
Vậy x = 41/35
d) 5/7 - 1/13 + 0,25 = 3(1/2) - x
5/7 - 1/13 + 1/4 = 7/2 - x
323/364 = 7/2 - x
x = 7/2 - 323/364
x = 951/364
Vậy x = 951/364
A = ( 2/7 . 1/4 - 1/3 . 2/7 ) : ( 2/7 . 3/9 - 2/7 . 2/5 )
A = 2/7 . [( 1/4 - 1/3 ) : ( 3/9 - 2/5 )]
A = 2/7 . [ -1/12 : -1/15 ]
A = 2/7 . 5/4
A = 5/14
B = ( 1/5 - 2/7 ) . 3/4 - 3/4 . ( 1/3 - 2/7 ) / 1/5 . 2/7 - 1/3 . ( 2/7 + 3/9 ) + 3/9 . 1/5
B = 3/4 - 3/4 / 3/9 + 3/9
B = 0 : 2/3
B = 0