Tính nhanh :
30a x 36 + 3b4 x 36 + 42c x 36
75% : 25% x 10% - 50%
Tính nhanh: a) ( 68 x 72 x 49) x ( 27 x 12 – 9 x 36 )
b) ( 25 x 50 – 125 x 10 ) x ( 1 + 2 + 3 + ……….. + 99 + 100
a: \(=68\cdot72\cdot49\cdot\left[324-324\right]=0\)
b: \(=\left(1250-1250\right)\cdot\left(1+...+100\right)=0\)
\(a,\left(68\times72\times49\right)\times\left(27\times12-9\times36\right)=\left(68\times72\times49\right)\times0=0\\ b,\left(25\times50-125\times10\right)\times\left(1+2+...+100\right)=0\times\left(1+2+...+100\right)=0\)
a, ( 68 × 72 × 49 ) × ( 27 × 12 − 9 × 36 ) = ( 68 × 72 × 49 ) × 0 =
b, ( 25 × 50 − 125 × 10 ) × ( 1 + 2 + ... + 100 ) = 0 × ( 1 + 2 + ... + 100 ) = 0
( 25 x 36) - 9 + 450 - 75 + 25
Tính nhanh
Tính nhanh:
100.000 - ( 47 x 75 + 47 x 24 + 47 )
276 x 50 + 276 x 36 + 1104
=100000-(47.(75+24+1) b) =276.(50+36+4)
=100000-4700 =276.90
=95300 =24840
\(100000-\left(47.75+47.24+47\right)\)
\(=100000-\left(47.75+47.24+47.1\right)\)
\(=100000-\left[47.\left(75+24+1\right)\right]\)
\(=100000-47.100\)
\(=100000-47000\)
\(=53000\)
\(276.50+276.36+1104\)
\(=276.50+276.36+276.4\)
\(=276.\left(50+36+4\right)\)
\(=276.90\)
\(=24840\)
100000-(47.75+47.24+47)
=100000-[47.(75+24+1)]
=100000-[47.(99+1)]
=100000-[47.100]
=100000-4700
=96300
276x50+276x36+1104
=276(50+36)+276.4
=276.86+276.4
=276.(86+4)
=276.90
=24840
a,
tìm x biết
x+36=98
x*8=56
b,
16+32
39+25
c, tính nhanh
36+69+31+64
12+78+25+75
ai nhanh mình tick
a ) x + 36 =98
x = 98 -36
x = 62
x * 8 = 56
x = 56 : 8
x = 7
b ) 16 + 32 = 48
39 + 25 = 64
c) tính nhanh :
36 + 69 + 31 + 64
= ( 36 + 64 ) + ( 69 + 31 )
= 100 + 100
= 200
12 + 78 + 25 + 75
= (12 + 78 ) + ( 25 + 75 )
= 90 + 100
= 190
a)62 va 7 b)48 va 64 c)200 vs 190
TK CHO MK NHA !
Tìm x :
a, x - ( 27 + 50 ) - ( -37 - 36 ) = 34
b, 25 - ( x + 8 ) - ( 15 + 10 ) = 36 + 10
a,x-77-(-73)=34
x-77 =34+(-73)
x-77 =-39
x =(-39)+77
x =38
b,25-(x+8)-25=46
25-(X+8) =46-25
25-(x+8) =21
x+8 =25-21
x+8 =4
x =4-8
x =-4
Tính nhanh
8 x 9 x 10 + 6 x 25 x12 + 4 x 18 x 66 - 2 x 36
Ta thấy: 8 x 9=72; 6 x 12=72; 4 x 18=72; 2 x 36=72.
Sử dụng tính chất phân phối của phép nhân với phép cộng.
Ta có: 72 x(10 + 25 + 66) - 72
= 72 x 101 - 72
= 7272 - 72
= 7200.
☘nat
Tính nhanh
8 x 9 x 10 + 6 x 25 x 12+ 4 x 18 x 66 - 2 x 36
A = 8 x 9 x 10 + 6 x 25 x 12 + 4 x 18 x 66 - 2 x 36
A = (8 x 9) x 10 + (6 x 12) x 25 + (4 x 18) x 66 - 2 x 36
A = 72 x 10 + 72 x 25 + 72 x 66 - 72
A = 72 x ( 10 + 25 + 66 - 1)
A = 72 x 100
A = 7200
1 tính nhanh
13 x 58 x 4 + 32 x 36 x2 +52 x 10
14 x 35 x 5 + 10x 25 x 7 +20 x 70
24 x (15 +49) +12x (50+42)
B1:Tính
a,3.52-16:22
b,22.17-23.14
c,15.141+59.10
d,17.85+15.17-120
e,100-[75-(7-2)]2
g,(23.94+93.45):(92.10-92)
B2:Tìm x
a,420+65.4=(x+175):3+30
b,96-3.(x+1)=42
c,(x-47)-115=0
d,(x-36):18=12
e,2x=16
B3:Tìm x
a,60-3.(x-2)=51
b,4x-20=25:22
c,8.6+288:(x-3)2=50
mk đang càn rất gấp
Bài 3:
a: Ta có: 60-3(x-2)=51
\(\Leftrightarrow x-2=3\)
hay x=5
b: Ta có: \(4x-20=25:2^2\)
\(\Leftrightarrow4x=\dfrac{25}{4}+20=\dfrac{105}{4}\)
hay \(x=\dfrac{105}{16}\)
c: Ta có: \(8\cdot6+288:\left(x-3\right)^2=50\)
\(\Leftrightarrow288:\left(x-3\right)^2=50-48=2\)
\(\Leftrightarrow\left(x-3\right)^2=144\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=12\\x-3=-12\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=15\\x=-9\end{matrix}\right.\)