Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
31 x 15 x 72 x 4 - 31 x 49 x 40
= 31 x 15 x 49 x 4 - 31 x 49 x 4 x 10
= 31 x 49 x 4 x ( 15 - 10)
= 31 x 49 x 4 x 5
...
31 x 15 x 7^2 x 4 - 31 x 49 x 40
= 31 x 15 x 49 x 4 - 31 x 46 x 40
= 31 x 49 x ( 15 x 4 - 40 )
= 31 x 49 x 20
= 30380
Tính nhanh:
a, 35x18 -5.7x28 = 35x18 -35x28 = 35 x (18 – 28) = 35 x ( -10) = -350
b,24x(16-5)-16x(24-5) = 24x16 – 24 x 5- 16x24 + 16x5 = (– 24 + 16)x 5 = -8 x 5 = -40
d,31x(-18)+31x(-81)-31 = 31x (-18 -81 – 1) = 31 x (-100) = -3100
e,(-12)x47+(-12)x52+(-12) = (-12)x (47+52 + 1)= (-12)x 100= - 1200
Ý c chưa rõ đề bài...
\(a.35\times18-5.7\times28\)
\(=35.18-35.28\)
\(=35.\left(18-28\right)\)
\(=35.\left(-10\right)\)
\(=-350\)
\(b.24.\left(16-5\right)-16.\left(24-5\right)\)
\(=24.16-24.5-16.24-16.5\)
\(=\left(24.16-16.24\right)-24.5-16.5\)
\(=0-\left(24+16\right).5\)
\(=0-40.5\)
\(=0-200\)
\(=-200\)
\(31.\left(-18\right)+31\left(-81\right)-31\)
\(=31\left(-18-81-1\right)\)
\(=31\left(-100\right)\)
\(=-3100\)
{\__/}
( • - •)
/ >🍟
31.(-18)+31-(-81)-31
31.(-18)+31+81+(-31)
31.(-18)+[31+(-31)]+81
-558+0+81
-477
k mình nha...kb nữa...^_^...thanks♥
= -558 + 31 + 81 - 31
= -558 + 81
= -477
CHÍNH XÁC ĐÓ, TK MK NHA
\(\left|-34\right|+(-4)\cdot(-1)^{2008}+(17-19)^2\)
\(=34+4+(-2)^2\)
\(=34+4+4\)
\(=42\)
\((-31)\cdot81-18\cdot31-31\)
\(=31\cdot(-81)-18\cdot31-31\)
\(=31\cdot(-81)-18-1\)
\(=31\cdot(-100)=-3100\)
Sửa đề : \(24x\left(31+14\right)=31x\left(24-14\right)\)
\(24x.45=31x.10\)
\(1080x=310x\)
\(1080x-310=0\)
\(770x=0\)
\(x=0\)
a, (-8)-(-12-8)=(-8)+12+8= [(-8)+8}]+12= 0+12=12
b, 1765-(312+1765)= 1765-312-1765=(1765-1765)-312=0-312=-312
c. (31-12)-(46+31-12)= 31-12+46-31+12= (31-31)+(12-12)+46=0+0+46=46
d, (5674-97)-5674=5674-97-5674=(5674-5674)-97=0-97=-97
e, (-1075)-(29-1075)=(-1075)+29+1075=[(-1075)+1075]+29=0+29=29
g, (18+29)+(158-18-29)=18+29+158-18-29=(18-18)+(29-29)+158=0+0+158=158
h, (13-135+49)-(13+49)=13-135+49-13-49=(13-13)+(49-49)-135=0+0-149=0-149=-149
Bài làm
31 x ( -72 ) - 31 x 70 + 31 x 2
= 31 x ( -72 + 70 + 2 )
= 31 x 0
= 0
31 . ( - 72 ) - 31. 70 + 31 . 2
= 31[ ( - 72 ) + 70 + 2 ]
= 31 [ (-72) + 72 ]
= 31 . 0 = 0
\(\left(-31\right).\left(-49\right)+34.31+18.\left(-31\right)\)
\(=\)\(\left(-31\right).\left(-49-34+18\right)\)
\(=\)\(\left(-31\right).\left(-65\right)\)
\(=\)\(2015\)