Tính nhanh
A=\(\frac{1\cdot5\cdot6+2\cdot10\cdot12+3\cdot15\cdot18+4\cdot20\cdot24+5\cdot25\cdot30}{1\cdot3\cdot5+2\cdot6\cdot10+3\cdot9\cdot15+4\cdot12\cdot20+5\cdot15\cdot25}\)
\(A=\frac{1.5\cdot6+2\cdot10\cdot12+3\cdot15\cdot18+4\cdot20\cdot24+5\cdot25\cdot30}{1\cdot3\cdot5+2\cdot6\cdot10+3\cdot9\cdot15+4\cdot12\cdot20+5\cdot15\cdot25}\)
=\(\frac{30\left(1+8+27+64+125\right)}{5\left(3+24+81+64+375\right)}\)
= \(\frac{30.225}{5.574}\)
=\(\frac{6750}{2870}\)
=\(\frac{675}{287}\)
K mình với!!!!
H=\(\frac{1\cdot2\cdot3+2\cdot4\cdot6+3\cdot6\cdot9+5\cdot10\cdot15}{1\cdot3\cdot6+2\cdot6\cdot12+3\cdot9\cdot18+5\cdot15\cdot30}\)= ?
H=\(\frac{1\cdot2\cdot3+2\cdot4\cdot6+3\cdot6\cdot9+5\cdot10\cdot15}{1\cdot3\cdot6+2\cdot6\cdot12+3\cdot9\cdot18+5\cdot15\cdot30}=\frac{1.2.3+2^3.\left(1.2.3\right)+3^3.\left(1.2.3\right)+5^3.\left(1.2.3\right)}{1.3.6+2^3.\left(1.3.6\right)+3^3.\left(1.3.6\right)+5^3.\left(1.3.6\right)}=\frac{1.2.3.\left(1+2^3+3^3+5^3\right)}{1.3.6.\left(1+2^3+3^3+5^3\right)}=\frac{2}{6}=\frac{1}{3}\)
Rút gọn biểu thức sau: \(\frac{1\cdot3\cdot5+2\cdot6\cdot10+3\cdot9\cdot15}{3\cdot5\cdot12+6\cdot10\cdot24+9\cdot15\cdot36}\)
\(\frac{1\cdot3\cdot5+2\cdot6\cdot10+3\cdot9\cdot15}{3\cdot5\cdot12+6\cdot10\cdot24+9\cdot15\cdot36}=\frac{1+1+1}{12+12+12}=\frac{3\cdot1}{3\cdot12}=\frac{1}{12}\)
A=\(A=\frac{1\cdot3\cdot5+2\cdot6\cdot10+4\cdot12\cdot20+7\cdot25\cdot35}{1\cdot5\cdot7+2\cdot10\cdot19+4\cdot20\cdot28+7\cdot35\cdot49}\)
* là dấu nhân
tính nhanh
\(\frac{1\cdot5\cdot6+2\cdot10\cdot12+4\cdot20\cdot24+9\cdot45\cdot54}{1\cdot3\cdot5+2\cdot6\cdot10+4\cdot2\cdot20+9\cdot27\cdot45}\)
\(\frac{1.5.6+2.10.12+4.20.24+9.45.54}{1.3.5+2.6.10+4.12.20+9.27.45}\)
\(=\frac{1.5.3.2+2.10.6.2+4.20.12.2+9.45.27.2}{1.3.5+2.6.10+4.12.20+9.27.45}\)
\(=\frac{2\left(1.3.5+2.6.10+4.12.20+9.27.45\right)}{1.3.5+2.6.10+4.12.20+9.27.45}\)
\(=2\)
Giá trị của biểu thức \(C=\frac{1\cdot5\cdot6+2\cdot10\cdot12+4\cdot20\cdot24+...+9\cdot45\cdot54}{1\cdot3\cdot5+2\cdot6\cdot10+4\cdot12\cdot20+...+9\cdot27\cdot45}\) là \(C=\)
\(C=\frac{1.5.3.2+2.10.6.2+4.20.12.2+...+9.45.27.2}{1.3.5+2.6.10+4.12.20+...+9.27.45}\)
\(C=\frac{2\left(1.5.3+2.10.6+4.20.12+...+9.45.27\right)}{1.3.5+2.6.10+4.12.20+...+9.27.45}\) = 2
\(a=\frac{2\cdot9\cdot8+3\cdot12\cdot10+4\cdot15\cdot12+...+98\cdot297\cdot200}{23\cdot4+3\cdot4\cdot5+4\cdot5\cdot6+...+98\cdot99\cdot100}\)
Tính a2
Tách phần lử trên ra sao cho có thể rút gọn với phần ơn dưới
Cho a=\(\dfrac{2\cdot9\cdot8+3\cdot12\cdot10+4\cdot15\cdot12+...+98\cdot297\cdot200}{2\cdot3\cdot4+3\cdot4\cdot5+4\cdot5\cdot6+...+98\cdot99\cdot100}\). Hỏi a có phải là nghiệm của đa thức P(x)=x^2-12x+35 không? Vì sao
\(\frac{2\cdot4\cdot10+4\cdot6\cdot8+14\cdot16\cdot20}{3\cdot6\cdot15+6\cdot9\cdot12+21\cdot24\cdot30}\)
CÁC BN LÀM HỘ MK NHÉ
\(\frac{2.4.10+4.6.8+14.16.20}{3.6.15+6.9.12+21.24.30}=\frac{2\left(1.2.5\right)+2\left(2.3.4\right)+2\left(7.8.9\right)}{3\left(1.2.5\right)+3\left(2.3.4\right)+3\left(7.8.9\right)}=\frac{2\left(1.2.5+2.3.4+7.8.9\right)}{3\left(1.2.5+2.3.4+7.8.9\right)}=\frac{2}{3}.\)
Hacker 2k6
Trả lời:
\(\frac{2.4.10+4.6.8+14.16.20}{3.6.15+6.9.12+21.24.30}\)
\(=\frac{2\left(1.2.5\right)+2\left(2.3.4\right)+2\left(7.8.10\right)}{3\left(1.2.5\right)+3\left(2.3.4\right)+3\left(7.8.10\right)}\)
\(=\frac{2\left(1.2.5+2.3.4+7.8.10\right)}{3\left(1.2.5+2.3.4+7.8.10\right)}\)
\(=\frac{2}{3}\)(Vì\(1.2.5+2.3.4+7.8.10\ne0\))
Hok tốt!
Good girl
\(\frac{2.4.10+4.6.8+14.16.20}{3.6.15+6.9.12+21.24.30}\)
\(=\frac{2\left(1.2.5\right)+2\left(2.3.4\right)+2\left(7.8.10\right)}{3.\left(1.2.5\right)+3.\left(2.3.4\right)+3\left(7.8.10\right)}\)
\(=\frac{2.\left(1.2.5+2.3.4+7.8.10\right)}{3.\left(1.2.5+2.3.4+7.8.10\right)}\)
\(=\frac{2}{3}\)
HOK TỐT