tính nhanh
b,49x37+49x15-52x14-52x15
c,43x32+{82x33+32[42x3+132:169+7(8-2)2}
a,(816-213)+(1315-773)-(315+416)
1^2+3^4+5^6+7^8+9^10=?
123+132+231+213+321+312=?
1.200.400.0=?
1^2+3^4+5^6+7^8+9^10=3492564909
1.200.400.0=0
1.tìm x
a)320+(218-x)=475
b)315-6/x=275
c)4*(x-15)+32=64
d)7*x+120/5=63
e)(120-4*x)*(x-17)=0
g)8*x-20=140
m)132-5*(20-x)=92
n)15*(44-2*x)=30
v)38/(2*x+18)=2
a)320 + ( 218-x)=475
( 218-x)=475-320
( 218-x)=155
x =218-155
x =63
b)315-6/x=275
6/x=315-275
6/x=40
x=40.6
x=240
c)4*(x-15)+32=64
4*(x-15) =64-32
4*(x-15) = 32
4*(x-15) =32:4
4*(x-15) =8
(x-15) =8:4
(x-15) =2
x =2+15
x =17
Đặt tính rồi tính:
a) 19 315 + 43 627 b) 79 371 – 47 849
c) 4 132 x 23 d) 1 929 : 32
200-1315:X 315+5.32+2022
Tính nhanh
M =119 + (-213) + 212 + (-118) + 2009.
N =223 + 132 + 187 - 23 -32 -27
1/ M= [119+(-118)] + [(-213)+212)] + 2009
M= 1 + -1 + 2009
M= 2009
2/ N = (223- 23) + (132 - 32) + (187-27)
N= 200 + 100 + 160
N= 300 + 160
N= 460
OLM duyệt đi
Tính nhanhB=3/2+9/4+25/8+65/8+.....+2041/2024
Tính hợp lý:
1, 1+(-4)+7+(-10)+13
2, -2+7+(-12)+17+(-22)
3, 44+45+46+47-24-25-26-27
4, (-213)+186+(-14)+217+54+(-49)
`@` `\text {Ans}`
`\downarrow`
`1,`
\(1+(-4)+7+(-10)+13\)
`= 1+(7+13)+(-4-10)`
`= 1+10-14`
`= 11-14`
`= -3`
`2, `
\(-2+7+(-12)+17+(-22)\)
`= -2+(7+17)+(-12-22)`
`= -2 + 24 - 24`
`= -2`
`3,`
\(44+45+46+47-24-25-26-27\)
`= (44 - 24)+(45 - 25) + (46 - 26)+(47 - 27)`
`= 20 + 20 + 20 + 20`
`= 40`
`4,`
\((-213)+186+(-14)+217+54+(-49)\)
`= (186 + 54)+(-213-14-49) + 217`
`= 240 - 276 + 217`
`= -36 + 217 = 181`
Tính nhanh
A= (5^4+4^7). (8^2-7^20) .(2^4-4^2)
B= (169-4^2).(169-5^2) ..... (169-14^2)
C = (7^2003+7^2002): 7^2001
Tính nhanh :
M= 199+(-213)+212+(-118)+2009 N=223+132+187-23-32-871.M=199+(-213)+212+(-118)+2009
M=(199+2009-118)+(212-213)
M=(2208-118)-1
M=2090-1=2089
2. N=223+132+187-23-32-87
N=(223-23)+(132-32)+(187-87)
N=200+100+100=400