Cho A =\(2\times4\times6\times8\times10\times12+40\) . Hỏi A có \(⋮6,⋮8,⋮5\) không ?
CHO \(A=2\times4\times6\times8\times10\times12^{10}+40\)
HỎI A CÓ CHIA HẾT CHO 6 ; CHO 8 ; CHO 5 KHÔNG ?
giúp mik gấp , ai nhanh mik cho tick và kết bạn
Tính nhanh:\(\frac{1\times2\times3+2\times4\times6+3\times6\times9+4\times8\times12+5\times10\times15}{1\times3\times5+2\times6\times10+3\times9\times15+4\times12\times20+5\times15\times25}-\frac{1+2+3+2+4+6+3+6+9+4+8+12+5+10+15}{1+3+5+2+6+10+3+9+15+4+12+20+5+15+25}\)
CHO A = \(\frac{2\times9\times8+3\times12\times10+4\times15\times12+...+98\times297\times200}{2\times3\times4+3\times4\times5+4\times5\times6+...+98\times99\times100}\)
TÍNH A\(^2\)
\(A=\frac{2\cdot9\cdot8+3\cdot12\cdot10+4\cdot15\cdot12+...+98\cdot297\cdot200}{2\cdot3\cdot4+3\cdot4\cdot5+4\cdot5\cdot6+...+98\cdot99\cdot100}\)
\(=\frac{2\cdot1\cdot3\cdot3\cdot4\cdot2+3\cdot1\cdot4\cdot3\cdot5\cdot2+...+98\cdot1+99\cdot3+100\cdot2}{2\cdot3\cdot4+3\cdot4\cdot5+...+98\cdot99\cdot100}\)
\(=\frac{1\cdot3\cdot2\cdot\left(2\cdot3\cdot4+3\cdot4\cdot5+...+98\cdot99\cdot100\right)}{2\cdot3\cdot4+3\cdot4\cdot5+...+98\cdot99\cdot100}\)
\(=1\cdot3\cdot2\)
\(=6\)
\(A^2=6^2=36\)
Bài 2: Tính
a) \(\dfrac{30\times25\times7\times8}{75\times8\times12\times14}\)
b)\(\dfrac{8\times3\times4}{16\times3}\)
c)\(\dfrac{4\times5\times6}{3\times10\times8}\)
(Các bạn tách các số ra rồi gạch, gạch xong thì nhân lại và ra kết quả) Thanks
a) \(\dfrac{30\times25\times7\times8}{75\times8\times12\times14}=\dfrac{3\times2\times5\times25\times7\times8}{25\times3\times8\times3\times4\times2\times7}=\dfrac{5}{3\times4}=\dfrac{5}{12}\)
b) \(\dfrac{8\times3\times4}{16\times3}=\dfrac{8\times3\times2\times2}{8\times2\times3}=2\)
c) \(\dfrac{4\times5\times6}{3\times10\times8}=\dfrac{4\times5\times3\times2}{3\times5\times2\times4\times2}=\dfrac{1}{2}\)
giúp mik với ạ, mình sẽ tick ạ! Thanks.
So sánh các số :
A=\(\frac{1\times2+2\times4+3\times6+4\times8+5\times10}{3\times4+6\times8+9\times12+12\times16+15\times20}\)
và
B=\(\frac{111111}{666665}\)
giải chi tiết giùm nha
A) \(\frac{1}{6}\) = 0,1666666665
B) 0,1666669167
\(\frac{1}{6}\) < \(\frac{111111}{666665}\)
Bạn lấy tử chia cho mẫu là ra
C=\(\frac{1\times5\times6+2\times10\times12+24\times8\times10}{1\times3\times5+2\times6\times10+8\times6\times20}\)
\(C=\frac{1.5.6+2.10.12+24.8.10}{1.3.5+2.6.10+8.6.20}\)
\(C=\frac{1.5.6.\left(1^3+2^3+8^2\right)}{1.3.5.\left(1^3+2^3+8^2\right)}=\frac{6}{3}=2\)
Bạn nên tách tử số và mẫu số ra thì sẽ tính được .
toán lop may the
\(y=\frac{1\times2\times3+2\times4\times6+4\times8\times12+8\times16\times24}{2\times3\times4+4\times6\times8+8\times12\times16+16\times24\times32}\frac{ }{ }\)
\(y=\frac{1x2x3+2x4x6+4x8x12+8x16x24}{2x3x4+4x6x8+8x12x16+16x24x32}\)
\(y=\frac{1}{4}\)
tích nha . Đúng 100% luôn.
tính :\(\frac{1}{1\times2\times3}+\frac{1}{2\times3\times4}+\frac{1}{3\times4\times5}+\frac{1}{4\times5\times6}+\frac{1}{5\times6\times7}+\frac{1}{6\times7\times8}+\frac{1}{7\times8\times9}+\frac{1}{8\times9\times10}\)
\(\frac{1}{1.2.3}+\frac{1}{2.3.4}+...+\frac{1}{8.9.10}=\frac{1}{2}.\left(\frac{1}{1.2}-\frac{1}{2.3}\right)+\frac{1}{2}.\left(\frac{1}{2.3}-\frac{1}{3.4}\right)+...+\frac{1}{2}.\left(\frac{1}{8.9}-\frac{1}{9.10}\right)\)
\(=\frac{1}{2}.\left(\frac{1}{1.2}-\frac{1}{2.3}+\frac{1}{2.3}-\frac{1}{3.4}+...+\frac{1}{8.9}-\frac{1}{9.10}\right)\)
\(\frac{1}{2}.\left(\frac{1}{1.2}-\frac{1}{9.10}\right)=\frac{1}{2}.\frac{22}{45}=\frac{11}{45}\)
Bài 4: Tính nhanh:
a, A =\(\left(\frac{84}{13}\right)^2+\left(\frac{35}{13}\right)^2\)
b, B = \(\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}\div\frac{3+\frac{3}{13}+\frac{3}{169}+\frac{3}{91}}{7+\frac{7}{13}+\frac{7}{169}+\frac{7}{91}}\)
c, C =\(\frac{1\times2+2\times4+3\times6+4\times8+5\times10}{3\times4+6\times8+9\times12+12\times16+15\times20}\)