sửa giùm mình đề câu a

a, 123+132+231+312+213+312

123+132+213+312+213+312

=(123+213)+(312+312)+(123+132)

= 123×2 + 312 ×2 + 255

= 426 + 624 +255

= 1050 + 255

= 1305

2) 159+195+519+591+915+951

=(159+951)+(519+591)+(195+915)

= 1110+1110+1110

= 1110×3

=3330

a) =1305 

 b)=3330 nha! cánh làm giống conan

Tính :

a) (-2) . (-7) . (-5)

= 14 . (-5)

= -70

b) 15 - 22 + ( -17 )

= (-7) + (-17)

= -24

c) 25 . (-4) - 20 . (-5)

= (-100) - (-100)

= 0

d) 185 - ( 49 + 185 )

= 185 - 234

= -49

e) (-19) . (-13) + 13 . (-29)

= 247 + -377

= -130

a) (-2) . (-7) . (-5)

= 14 . (-5)

= -70.

b) 15 - 22 + (-17)

= (-7) + (-17)

=-24.

c)25. (- 4) – 20. (- 5)

= (-100) - (-100)

= (-100) + 100

= 0

d) 185 – (49 + 185)

= 185 - 234

= (-49).

e) ( -19 ) . (- 13) + 13 . (-29)

= 247 + ( -377).

= ( -130)

\(a,\left(-2\right).\left(-7\right).\left(-5\right).\)

\(=\left[\left(-2\right).\left(-5\right)\right].\left(-7\right).\)

\(=10.\left(-7\right)=\left(-70\right).\)

\(b,15-22+\left(-17\right).\)

\(=\left(-7\right)+\left(-17\right)=\left(-24\right).\)

\(c,25.\left(-4\right)-20.\left(-5\right).\)

\(=\left(-100\right)-\left(-100\right)=\left(-100\right)+100=0.\)

\(d,185-\left(49+185\right).\)

\(=185-49-185.\)

\(=\left(185-185\right)-49.\)

\(=0-49=\left(-49\right).\)

\(e,\left(-19\right).\left(-13\right)+13.\left(-29\right).\)

\(=\left(-19\right).\left(-13\right)+\left(-13\right).29.\)

\(=\left[\left(-19\right)+29\right]\left(-13\right).\)

\(=10.\left(-13\right)=\left(-130\right).\)

~ Học tốt ~

mn ơi giúp mik đi huhu

mn nêu cách làm ra giúp tớ nha

a)\(2^4-50:25+13.7\)\(=16-2+91=14+91=105\)

b) \(32+5.13-3.2^3=32+65-3.8=97-24=75\)

c) \(2.\left[\left(195+35:7\right):8+195\right]-400\)

\(=2.\left[\left(195+5\right):8+195\right]-400\)

\(=2.\left(200:8+195\right)-400=2.\left(25+195\right)-400\)

\(=2.\left(220\right)-400=440-400=40\)

5) (-19).(-13)+13.(-29)

=19.13+13.(-29)

=13.[19+(-29)]

=13.(-10)

=-130

10) 3.(-2)²+4.(-5)+20

=3.4-20+20

=12+0

=12

`1, -2/9 xx 15/17 + (-2/9) xx 2/17`

`= -2/9 xx (15/17 + 2/17)`

`= -2/9 xx 17/17`

`=-2/9xx1`

`=-2/9`

__

`-5/3 xx 6/5 + (-7/9) xx 3/10`

`= -30/15 + (-21/90)`

`= -2 + (-7/30)`

`=-60/30 +(-7/30)`

`=-67/30`

__

`15/20 xx 7/5 + (-9/7) xx (-6/4)`

`=3/4 xx7/5 + (-9/7) xx(-6/4)`

`= 21/20 + 54/28`

`= 21/20 + 27/14`

`=417/140`

__

`-25/13 xx 5/19 + (-25/13) xx 14/19`

`=-25/13 xx (5/19 +14/19)`

`=-25/13 xx 19/19`

`= -25/13 xx 1`

`=-25/13`

__

`-7/13 xx 13/5 + (-9/7) xx 5/3`

`=-7/5 +(-15/7)`

`=-124/35`

\(\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).\left(2^4-4^2\right)\)

\(=\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).\left(16-16\right)\)

\(=\left(2^{17}+7^2\right).\left(9^{15}-3^{15}\right).0\)

\(=0\)

-------------------------------------------------

\(\left(7^{1997}-7^{1995}\right):\left(7^{1994}.7\right)\)

\(=\left[7^{1995}\left(7^2-1\right)\right]:7^{1995}\)

\(=7^{1995}.48:7^{1995}\)

\(=48\)

-------------------------------------------------

\(\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left(3^8-81^2\right)\)

\(=\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).\left(6561-6561\right)\)

\(=\left(1^2+2^3+3^4+4^5\right).\left(1^3+2^3+3^3+4^3\right).0\)

\(=0\)

-------------------------------------------------

\(\left(2^8+8^3\right):\left(2^5.2^3\right)\)

\(=\left[2^8+\left(2^3\right)^3\right]:2^8\)

\(=\left(2^8+2^9\right):2^8\)

\(=2^8.\left(1+2\right):2^8\)

\(=2^8.3:2^8\)

\(=3\)

sos

\((2^{17}+17^{2}).(9^{15}-3^{15}).(2^{4}-4^{2})\)

\(=(2^{17}+17^{2}).(9^{15}-3^{15}).(16-16)\)

\(=(2^{17}+17^{2}).(9^{15}-3^{15}).0\)

\(=0\)

\((7^{1997}-7^{1995}):(7^{1994}.7)\)

\(=(7^{1997}-7^{1995}):7^{1995}\)

\(=7^{1997}:7^{1995}-7^{1995}:7^{1995}\)

\(=7^{2}-1=49-1=48\)

\(1^{2}+2^{3}+3^{4}+4^{5}).(1^{3}+2^{3}+3^{3}+4^{3}).(3^{8}-81^{2})\)

\(=(1^{2}+2^{3}+3^{4}+4^{5}).(1^{3}+2^{3}+3^{3}+4^{3}).(6561-6561)\)

\(=(1^{2}+2^{3}+3^{4}+4^{5}).(1^{3}+2^{3}+3^{3}+4^{3}).0\)

\(=0\)

\((2^{8}+8^{3}):(2^{5}.2^{3})\)

\(=[2^{8}+(2^{3})^{3}]:2^{8}\)

\(=(2^{8}+2^{9}):2^{8}\)

\(=2^{8}:2^{8}+2^{9}:2^{8}\)

\(=1+2=3\)