(3/7)^21 : (4/49)^6
4×7/9×23
2×21/14×15
2×5×13/26×35
9×6-9×3/18
17×5-17/3-20
49+7×49/49
2×3×5+4×9×25+6×9×35+10×21×40
_____________________________________
2×3×7+4×9×35+6×9×49+10×21×56
11/15 + 8/15= Tính phân số
6/7 - 5/21=
25/4 x 16/100
7 x 2/49 =
4/3 : 2/9
5/8 : 25 =
11/15 + 8/5= Tính phân số
6/7 - 5/21=
25/4 x 16/100
7 x 2/49 =
4/3 : 2/9
5/8 : 25 =
2/3 + 3/4
9/4 + 3/5
5/24 + 1/4
3/15 - 5/35 18/27 - 2/6 37/12 - 3
11/9 x 3/22 7/13 x 13/7 4 x6/7
2/5 : 3/10 3/8 : 9/4 8/21 : 4/7
2/3 + 3/4=17/12
9/4 + 3/5=57/20
5/24 + 1/4=11/24
3/15 - 5/35=2/35 18/27 - 2/6=1/3 37/12 - 3=1/12
11/9 x 3/22=1/6 7/13 x 13/7=1 4 x6/7=24/7
2/5 : 3/10=4/3 3/8 : 9/4=1/6 8/21 : 4/7=2/3
2/3 + 3/4
= 17/12
9/4 + 3/5
= 57/20
5/24 + 1/4
=11/24
3/15 - 5/35
=2/35
18/27 - 2/6
=1/3
37/12 - 3
= 1/12
11/9 x 3/22
=1/6
7/13 x 13/7
=1
4 x6/7
=24/7
2/5 : 3/10
=4/3
3/8 : 9/4
=1/6
8/21 : 4/7
= 2/3
1=17/12
2=57/20
3=11/24
4=2/35 7=1/3 10=1/12
5=1/6 8=1 11=24/7
6=4/3 9=1/6 12=2/3
Tính giá trị biểu thức :
A = 6/8 . 8/13 + 6/13 . 9/7 - 3/13 . 6/7
B = ( 5/4 + 3/4 ) . 4/7 . ( 3/4 + 9/4 ) . 4/7
C = -5/7 . 1/35 + 6/49 . ( -8 ) + 16/(-3) . (-3)/8
D = ( 5/10 + 21/28 - 60/72 ) . 24/5
các bạn làm ơn giúp mình với đc ko , mình đang cần gấp !!!!
Trả lời:
\(A=\frac{6}{8}.\frac{8}{13}+\frac{6}{13}.\frac{9}{7}-\frac{3}{13}.\frac{6}{7}\)
\(A=\frac{6}{13}+\frac{54}{91}-\frac{18}{91}\)
\(A=\frac{6}{7}\)
\(B=\left(\frac{5}{4}+\frac{3}{4}\right).\frac{4}{7}.\left(\frac{3}{4}+\frac{9}{4}\right).\frac{4}{7}\)
\(B=\frac{2}{1}.\frac{4}{7}.\frac{3}{1}.\frac{4}{7}\)
\(B=\frac{8}{7}.\frac{12}{7}\)
\(B=\frac{96}{49}\)
tính nhanh
53* 39+47*39-53*21-47*21
2*53*12+4*6*87-3*8*40
5*7*77-7*60+49*25-15*42
53x39+47x39-53x21-47x21
=39x ( 53+47) - 21x(53+47)
=39 x100 - 21x100
= 100x(39-21)
=100x18
=1800
2x53x12 +4x6x87 - 3x8x40
= (2x12)x53 + (4x16)x87 - (3x8) x40
= 24x53 + 24x87 + 24x40
= 24( 53+87+40)
= 24x180
=4320
a,53*39+47*39-53*21-47*21
=39*[53+47]-21*[53+47]
=39*100-21*100
=3900-2100
=1800
b,2*53*12+4*6*87-3*8*40
=[2*12]*53+[4*6]*87-[3*8]*40
=24*53+24*87-24*40
=24*[53+87-40]
=24*100
=2400
(3/7)^21:(9/49)/6
Lời giải:
\((\frac{3}{7})^{21}:(\frac{9}{49})^6=(\frac{3}{7})^{21}:[(\frac{3}{7})^2]^{6}=(\frac{3}{7})^{21}:(\frac{3}{7})^{12}\\
=(\frac{3}{7})^{21-12}=(\frac{3}{7})^9\)
tính nhanh:
a:53*39+47*39-53*21-47*21
b:2*53*12+4*6*87-3*8*40
c:5*7*77-7*60+49*25-15*42
( 3/7 )^21 : ( 9/49 )^6
(3/7)^21 : (9/49)^6 = (3/7)^21 : (3/7 *3/7)^6= (3/7)^21 : (3/7)^12 = 3/7^9