395 : 5 + 75 x 4
Tính nhanh
A= ( 38 x 333 - 111 x 133 ) x 2018
B = ( 25 + 3 x 75 - 125 x 2 ) : 20182019
C = ( 244 x 395 - 244 x 195 ) : ( 122 x 200 )
D = ( 355 x 45 x 55 ) : ( 11 x 9 x 7)
E = 1 x 2 + 2 x 3 + 3 x 4 + 4 x 5 + ... + 49 x 50
a: \(A=\left[111\cdot\left(38\cdot3-133\right)\right]\cdot2018\)
\(=111\cdot\left(-19\right)\cdot2018=-4255962\)
b: \(B=\left[25\left(1+3\cdot3-5\cdot2\right)\right]:20182019\)
\(=25\left(1+9-10\right):20182019=0\)
c: \(C=\dfrac{\left[244\left(395-195\right)\right]}{122\cdot200}=\dfrac{244}{122}=2\)
d: \(D=\dfrac{355\cdot45\cdot55}{11\cdot9\cdot7}=\dfrac{355\cdot5\cdot5}{7}=\dfrac{8875}{7}\)
1-(7/4+5/3)/(3/4-5/7)=
2-395/2*7+158*x=0
1 , Tìm X
A , ( 1000 - 333 × X ) × 1000 - 999 = 1
B , 75% × X = 1
2, Tính
A , M = 50% × 1 1/3 × 10 × 7/35
B , 40404/70707 + 244 × 395 - 151 / 244 + 395 × 243
C , ( 158 × 68 - 158 × 58 ) : 11 : 10
395 x15 + 83 x 395 + 395 x 2
395 x 15 + 83 x 395 + 395 x 2
= 395 x (15 + 83 + 2)
= 395 x 100
= 39500.
\(395\times15+83\times15+395\times2=395\times\left(83+15+2\right)=395\times100=39500\)
Tính bằng cách thuận tiện nhất:
1975 x 37 + 395 x 5 x 24 - 1975 + 3950 x 15
\(1975\times37+395\times5\times24-1975+3950\times15\)
\(=1975\times37+1975\times24-1975\times1+1975\times30\)
\(=1975\times\left(37+24-1+30\right)\)
\(=1975\times90=177750\)
244 x 395 - 151/244 + 395 x 243
\(\frac{244\times395-151}{244+395\times243}\)
\(=\frac{243\times395+395-151}{243\times395+244}\)
\(=\frac{243\times395+244}{243\times395+244}\)
\(=1\)
Tính:
a) (12 + 8) x 4 = .........................
= .........................
12 + 8 x 4 = .........................
= .........................
b) 25 + 75 : 5 = .........................
= .........................
(25 + 75) : 5 = .........................
= .........................
a) (12 + 8) x 4 = 20 x 4
= 80
12 + 8 x 4 = 12 + 32
= 44
b) 25 + 75 : 5 = 25 + 15
= 40
(25 + 75) : 5 = 100 : 5
= 20
Tính bằng cách hợp lí
248 : 4 + 152 : 4
4125 : 5 - 395 : 5
Bài làm
a) 248 : 4 + 152 : 4
= ( 248 + 152 ) : 4
= 400 : 4
= 100
b) 4125 : 5 - 395 : 5
= ( 4125 - 395 ) : 5
= 3730 : 5
= 746
248+4+152:4
=(248+152):4
=400:4=100
4125:5-395:5
=(4125-395):5
=3730:5=746.
Dễ vậy mà ko biết !!!!!
Tính nhanh (244 X 395 - 151) / (244 + 395 X 243) . So sánh phân số với 1
244 * 395 - 151
244 + 395 * 243
244x395-151=96229
244+395x243=96229
k mk nha