2.31.12 + 4.42.6 + 8.81 =?
tinh nhanh:
a,17.85+15.17-120
b.2.31.12+4.42.6+8.81
c.8.17-8.14+3.42
d.4.15.17+5.12.17+6.10.56
17.( 85+15)-120=15.100-120=1500 -120=1380
Bạn gom số lại là được nhé tick nhé
1.So sánh: 3.tinh nhanh:(hoac tinh binh thuong^^)
a.63^15&34^18 a.17.85+15.17-120
b.83^9&26^12 b.2.31.12+4.42.6+8.81
(CÁC BN TÁCH RA GIÙM M NHÉ) c.8.17-8.14+3.42
2.tìm x: d.4.15.17+5.12.27+6.10.56
x+2.x+3.x=...+100.x=15150
Rút gọn phân số : a) M = 9^4.27^5.3^6.3^4/3^8.81^4.234.8^2
Lời giải:
\(M=\frac{9^4.27^5.3^6.3^4}{3^8.81^4.234.8^2}=\frac{(3^2)^4.(3^3)^5.3^6.3^4}{3^8.(3^4)^4.2.3^2.13.(2^3)^2}\)
\(=\frac{3^8.3^{15}.3^6.3^4}{3^8.3^{16}.2.3^2.13.2^6}=\frac{3^{33}}{3^{26}.2^7.13}=\frac{3^7}{2^7.13}\)
thực hiện phép tính(tính nhanh nếu có thể):
1428:{23-[(8.81-369):31]}
1428:{23-[(8.81-369):31]}
= 1428 : { 23 - [ 279 : 31 ] }
= 1428 : { 23 - 9 }
= 1428 : 14
= 102
1428:{23-[(8.81-369):31]}
=1428:{23-[(648-369):31]}
=1428:{23-[279:31]}
=1428:{23-9}
=1428:14
=102
Học tốt~
\(\dfrac{8^3.9^4-\left(-2\right)^8.81^2}{16^2.81^2+4^4.27^3}\)
giúp em với mng =(
\(=\dfrac{\left(2^3\right)^3.\left(3^2\right)^4-2^8.\left(3^4\right)^2}{\left(2^4\right)^2.\left(3^4\right)^2+\left(2^2\right)^4.\left(3^3\right)^3}=\dfrac{2^9.3^8-2^8.3^8}{2^8.3^8+2^8.3^9}=\)
\(=\dfrac{2^8.3^8.\left(2-1\right)}{2^8.3^8.\left(1+3\right)}=\dfrac{1}{4}\)
2.31.12+4.6.42+8.27.3
2.31.12+4.6.42+8.27.3
= (2.12).31+(4.6).42+(8.3).27
= 24.31+24.42+24.27
= 24.(31+42+27)
= 24.100
= 2400
_HT_
2.31.12+4.6.42+8.27.3
2.31.12+4.6.42+8.27.3
=24.31+24.42+27.24
=24.(31+42+27)
=24.100
=2400
2.31.12+4.6.42+8.27.3 = ?
2.31.12+4.6.42+8.27.3 = 24x31+24x42+24x27=24x(31+42+27)=24x100=2400 nha Dương Ngọc Phuong Linh
Tính nhanh: 2.31.12 + 4.6.42 + 8.27.3
2.31.12 + 4.6.42 + 8.27.3
= ( 2.12). 31 + ( 4. 6).42 + (8.3). 27
= 24.31 + 24.42 + 24.27
= 24.(31 + 42 + 27) = 24.100 = 2400