Cho A=-543/547;B=-789/792
Trong 2 số A và B số nào lớn hơn
Tính giá trị của biểu thức ;
A=2/1/547 x 3/211 - 546/547 x 1/211 - 4/547x211
Tính bằng cách thuận tiện nhất:
a. 17 x 543 + 83 x 543
b. 318 x 963 + 682 x 963
Hướng dẫn giải:
a.
17 x 543 + 83 x 543
= (17 + 83) x 543
= 100 x 543
= 54300
b.
318 x 963 + 682 x 963
= (318 + 682) x 963
= 1000 x 963
= 963000
a)17x543+83x543
=(17+83)x543
=100x543
=54300
b)318x963+682x963
=(318+682)x963
=1000x963
=963000
Tính:
\(2\dfrac{1}{547}\cdot\dfrac{3}{211}-\dfrac{546}{547}\cdot\dfrac{1}{211}-\dfrac{4}{547\cdot211}\)
\(2\dfrac{1}{547}.\dfrac{3}{211}-\dfrac{546}{547}.\dfrac{1}{211}-\dfrac{4}{547.211}\)
\(=\left(2+\dfrac{1}{547}\right).3.\dfrac{1}{211}-\left(1-\dfrac{1}{547}\right).\dfrac{1}{211}-4.\dfrac{1}{547}.\dfrac{1}{211}\)
Đặt \(a=\dfrac{1}{547};b=\dfrac{1}{211}\)
Thay \(a=\dfrac{1}{547};b=\dfrac{1}{211}\) vào biểu thức trên , ta được :
\(\left(2+a\right).3b-\left(1-a\right)b-4ab\)
\(=6b+3ab-b+ab-4ab\)
\(=5b\)
\(=5.\dfrac{1}{211}\)
\(=\dfrac{5}{211}\)
Vậy g/t biểu thức trên là : \(\dfrac{5}{211}\)
Tính giá trị của các biểu thức sau
a) M= \(2\frac{1}{315}\cdot\frac{1}{651}-\frac{1}{105}\cdot3\frac{650}{651}-\frac{4}{315\cdot651}+\frac{4}{105}\)
b) N= \(2\frac{1}{547}\cdot\frac{3}{211}-\frac{546}{547}\cdot\frac{1}{211}-\frac{4}{547\cdot211}\)
a: \(M=\dfrac{631}{315}\cdot\dfrac{1}{651}-\dfrac{1}{105}\cdot\dfrac{2603}{651}-\dfrac{4}{315\cdot651}+\dfrac{4}{105}\)
\(=\dfrac{1}{315\cdot651}\cdot\left(631-4\right)-\dfrac{1}{105}\left(\dfrac{2603}{651}-4\right)\)
\(=\dfrac{1}{105}\cdot\dfrac{1}{1953}\cdot627+\dfrac{1}{105\cdot651}\)
\(=\dfrac{1}{105\cdot651}\left(\dfrac{1}{3}\cdot627+1\right)=\dfrac{1}{105\cdot651}\cdot210=\dfrac{2}{651}\)
b: \(N=\dfrac{1095}{547}\cdot\dfrac{3}{211}-\dfrac{546}{547\cdot211}-\dfrac{4}{547\cdot211}\)
\(=\dfrac{1}{547\cdot211}\left(1095\cdot3-546-4\right)\)
\(=\dfrac{1}{547\cdot211}\cdot2735=\dfrac{5}{211}\)
543 * 45 + 543 *35 =
543x45+543x35
= 543x(45+35)
= 543x80
=43440
Tính NHANH :
a.125-(27-75+73)
b.314-(21-86+79)
c.728-(211-72+89)
d.(547-623)-(547-23)
a.125-(27-75+73)
= 125 - (27 + 73 - 75)
= 125 - (100 - 75)
=125 - 25
=100
b.314-(21-86+79)
= 314 - (21 + 79 - 86)
= 314 - (100 - 86)
= 314 - 14
= 300
c.728-(211-72+89)
= 728 - (211 + 89 -72)
= 728 - (300 - 72)
= 728 - 28
= 700
d.(547-623)-(547-23)
= 547 - 623 - 547 + 23
= 547 - 547 + 23 - 623
= 0 + -600
= - 600
a)125-(27-75+73)=125-27+75-73=(125+75)-(27+73)=200-100=100. b)314-(21-86+79)=314-21+86-79=(314+86)-(21+79)=400-100=300. c) 728-(221-72+89)=(728+72)-(221+89)=800-300=500. d) (547-623)-(547-23)=547-623-547+23=(547-547)+(23-623)=0+(-600)=-600
(A x1 -a:1): ( a x 1883+543)
( a x 1 - a x 1 ) : ( a x 1883 + 543 )
= ( a - a ) : ( a x 1883 + 543 )
= 0 : a x 1883 + 543
= 0 x 1883 + 543
= 0 + 543
= 543.
\(\left(a\times1-a:1\right):\left(a\times1883+543\right)\\ =\left(a-a\right):\left(a\times1883+543\right)\\ =0:\left(a\times1883+543\right)\\ =0\)
543 x 46 + 54 x 543 -14300
\(543x46+54x543-14300\)
\(=543x\left(46+54\right)-14300\)
\(=543x100-14300\)
\(=54300-14300\)
\(=40000\)
Học Tốt !
\(=543\cdot\left(46+54\right)-14300=543\cdot100-14300\)
\(=54300-14300=40000\)
( 129-a) ×543 =51042
(129-a).543=51042
129-a=51042:543
129-a=94
a=129-94
a=35
học tốt nha bn
(129-a) x 543 = 51042
=> 129 - a = 51042 :543
=> 129 - a = 94
=> a = 129 - 94
=> a = 35
\(\left(129-a\right)\times543=51042\)
\(\Leftrightarrow129-a=94\)
\(\Leftrightarrow a=35\)