Tính hợp lí
a) \(\left(-12\right).\left(-13\right)+13.\left(-29\right)\)
b) \(-23.63+23.21-58.23\)
Tính:
\(-3^2+\left\{-54:\left[-2^8+7\right]\cdot\left(-2\right)^2\right\}\)
Tính hợp lí :
\(31\cdot\left(-18\right)+31\cdot\left(-81\right)-31\)
\(\left(-12\right)\cdot47+\left(-12\right)\cdot52+\left(-12\right)\)
\(13\cdot\left(23+22\right)-3\cdot\left(17+28\right)\)
\(-48+48\cdot\left(-78\right)+48\cdot\left(-21\right)\)
`#3107.101107`
`-3^2 + {-54 \div [-2^8 + 7] * (-2)^2}`
`= -9 + [-54 \div (-256 + 7) * 4]`
`= -9 + [-54 \div (-249) * 4]`
`= -9 + (18/83 * 4)`
`= -9 + 72/83`
`= -675/83`
______
`31 * (-18) + 31 * (-81) - 31`
`= 31 * (-18 - 81 - 1)`
`= 31 * (-100)`
`= -3100`
___
`(-12) * 47 + (-12) * 52 + (-12)`
`= (-12) * (47 + 52 + 1)`
`= (-12) * 100`
`= -1200`
___
`13 * (23 + 22) - 3 * (17 + 28)`
`= 13 * 45 - 3 * 45`
`= 45 * (13 - 3)`
`= 45 * 10`
`= 450`
____
`-48 + 48 * (-78) + 48 * (-21)`
`= 48 * (-1 - 78 - 21)`
`= 48 * (-100)`
`= -4800`
Tính hợp lí (nếu có thể)
a 15+23+(-25)+(-23)
b -23.63+23.21-58.23
a,15+23+(-25)+(-23)=[ (-23)+23] +[(-25)+15] = 0+(-10)= -10
b,-23.63+23.21-58.23=23.(-63)+23.21-58.23=23.(-63+21-58)=23.(-100)=-2300
a)
15 + 23 + ( -25 ) + ( -23 )
= [ 15 + ( -25 ) ] + [ 23 + ( -23 ) ]
= -10 + 0
= -10.
b)
-23.63 + 23.21 - 58.23
= -23 . ( 63 - 21 + 58 )
= -23 . 100
= -2300.
Tính hợp lí:
-23.63+23.21-58.23
Giúp mk nha!!
^-^
-23.63+23.21-58.23
= 23. (-63) + 23.21 - 58.23
= 23.( -63 + 21-58)
= 23. (-100)
= -2300
-23.63+23.21-58.23=23.-63+23.21-58.23=23(-63+21-58)=23.-100=-2300
\(-23.63+23.21-58.23\)
\(=-63.23+21.23-58.23\)
\(=23.\left(21-58-63\right)\)
\(=23.\left(-100\right)\)
\(=-2300\)
Bỏ dấu ngoặc rồi tính :
a) \(\left(18+29\right)+\left(158-18-29\right)\)
b) \(\left(13-135+49\right)-\left(13+49\right)\)
a, (18+29) +(158-18-29)
= 18+29+158-18-29
= (18-18) +(29-29)+ 158
= 158
b, (13-135+49)- (13+49)
= 13-135+49-13-49
= (13-13) +(49-49) -135
= 135
a, \(\left(18+29\right)+\left(158-18-29\right)\)
\(=18+29+158-18-29\)
\(=\left(18-18\right)+\left(29-29\right)+158\)
\(=158\)
b,
\(\left(13-135+49\right)-\left(13+49\right)\)
\(=13-135+49-13-49\)
= \(\left(13-13\right)+\left(49-49\right)-135\)
= \(-135\)
a) (18+29)+(158-18-29)
=18-29+185-18-29
=(18-18)+(18-18)-158
=0+0-158
=-158
b)(13-135+49)-(13+49)
=13-135+49-13-49
=(13-13)+(49-49)-153
=0+0-153
=-153
tính hợp lí
\(\left[\left(25\frac{12}{67}+9\frac{13}{41}\right)_{ }-\left(8\frac{12}{67}-3\frac{28}{41}\right)\right]X\frac{21}{-13}\)
làm ơn giúp mk nhanh nhé mai mk đi học rồi
\(=\left(25+\dfrac{12}{67}+9+\dfrac{13}{41}-8-\dfrac{12}{67}+3+\dfrac{28}{41}\right)\cdot\dfrac{-21}{13}\)
\(=\left(25+9-8+3+1\right)\cdot\dfrac{-21}{13}=\dfrac{-630}{13}\)
Tính :
a) \(29.\left(-13\right)+27.\left(-27\right)+\left(-14\right).\left(-29\right)\)
b) \(17.\left(-37\right)-23.37-46.\left(-37\right)\)
Sao chỉ có mỗi tính thôi mà bạn cũng không làm được?
Tính bằng cách hợp lí :
\(A=\left(-5,85\right)+\left\{\left[\left(+41,3\right)+\left(+5\right)\right]+\left(+0,85\right)\right\}\)
\(B=\left(-87,5\right)+\left\{\left(+87,5\right)+\left[\left(+3,8\right)+\left(-0,8\right)\right]\right\}\)
\(C=\left[\left(+9,8\right)+\left(-13\right)\right]+\left[\left(-5\right)+\left(+8,5\right)\right]\)
\(A=\left(-5,85\right)+\left\{\left[\left(+41,3\right)+\left(+5\right)\right]+\left(+0,85\right)\right\}\)
\(A=\left(-5,85\right)+\left\{\left[41,3+5\right]+0,85\right\}\)
\(A=\left(-5,85\right)+\left\{41,3+5+0,85\right\}\)
\(A=\left(-5,85\right)+\left\{41,3+5,85\right\}\)
\(A=\left(-5,85\right)+41,3+5,85\)
\(A=\left(-5,85\right)+5,85+41,3\)
\(A=0+41,3\)
\(A=41,3\)
\(B=\left(-87,5\right)+\left\{\left(+87,5\right)+\left[\left(+3,8\right)+\left(-0,8\right)\right]\right\}\)
\(B=\left(-87,5\right)+87,5+3,8+\left(-0,8\right)\)
\(B=\left[\left(-87,5\right)+87,5\right]+\left[3,8+\left(-0,8\right)\right]\)
\(B=0+3\)
\(B=3\)
\(C=\left[\left(+9,8\right)+\left(-13\right)\right]+\left[\left(-5\right)+\left(+8,5\right)\right]\)
\(C=\left(-3,2\right)+3,5\)
\(C=0,3\)
1.Tính hợp lí:
a, [ 13-17 ].[-10]+[-7]0
b, 72.[28-49] + 28.[-49-72]
c, -65.[87-17] - 87.[17-65]
d, -23.63+23.21-58.23
e, 25.134+25.[-34]
Giúp mình với mình đang cần gấp!
a, [ 13-17 ].[-10]+[-7]0
=-4.[-10]+1
=40+1
=41
b, 72.[28-49] + 28.[-49-72]
=72.[-21]+28.[-121]
=-1512+[-3388]
=-4900
c, -65.[87-17] - 87.[17-65]
=-65.70-87.[-48]
=4550-[-4276]
=8726
d, -23.63+23.21-58.23
=23.(-63)+23.21-58.23
=23.(-63+23-58)
=23.(-40-58)
=23.(-98)
=-2254
e, 25.134+25.[-34]
=25.[134+(-34)]
=25.100
=2500
Tính hợp lý:
\(A=\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}\) \(B=\left(\dfrac{4}{5}+\dfrac{1}{2}\right):\left(\dfrac{3}{13}-\dfrac{8}{13}\right)\)
\(C=\left(\dfrac{2}{3}-\dfrac{1}{4}+\dfrac{5}{11}\right):\left(\dfrac{5}{12}+1-\dfrac{7}{11}\right)\)
a: \(A=\dfrac{7}{12}+\dfrac{5}{72}-\dfrac{11}{36}=\dfrac{42}{72}+\dfrac{5}{72}-\dfrac{22}{72}=\dfrac{25}{72}\)
b: \(B=\dfrac{8+5}{10}:\dfrac{-5}{13}=\dfrac{13}{10}\cdot\dfrac{13}{-5}=-\dfrac{169}{100}\)
c: \(C=\left(\dfrac{88}{132}-\dfrac{33}{132}+\dfrac{60}{132}\right):\left(\dfrac{55}{132}+\dfrac{132}{132}-\dfrac{84}{132}\right)\)
\(=\dfrac{88-33+60}{55+132-84}=\dfrac{115}{103}\)