Tính nhanh :
\(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right).\frac{21}{24}\)
a,\(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right)\frac{21}{24}\)
Tính :
a) A = 1.2.3 . ..... . 100 - 1.2.3. ... .99 - 1.2.3.98.992
b) B = \(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right).\frac{21}{24}\)
Bạn nào làm đúng , nhanh mk tick cho
b)B=(136/15 - 28/5 +31/5).21/24
B=(136/15-(28/5 - 31/5).21/24
B=(136/15 + 3/5).21/24
B=29/3.21/24
B=203/24
\(A=1.2.3...100-1.2.3...99-1.2.3...98.99^2\)
\(=1.2.3...99\left(100-1-99\right)\)
\(=1.2.3...99.0=0\)
Thực hiện phép tính để tính giá trị các biểu thức sau:
\(a,A=\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right).\frac{21}{24}\)
\(b,B=70.\left(\frac{131313}{565656}+\frac{131313}{727272}+\frac{131313}{909090}\right)\)
\(c,C=\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.2}+\frac{1}{2.15}+\frac{13}{15.4}\)
a) A= ( 136/15 - 28/5 + 62/10) .21/24
A= (136/15 - 84/15 + 93/15) . 7/8
A= 145/15. 7/8
A= 203/24
b) B= 70 .( 131313.565656 + 131313/727272 + 131313/ 909090)
= 70. ( 13/56+ 13/72 + 13/90)
= 70 . 39/70
= 39
(\(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\)) .\(\frac{21}{24}\)
\(\left(\frac{136}{15}-\frac{28}{5}+\frac{62}{10}\right)\cdot\frac{21}{24}\)
=
\(=\left(\frac{272}{30}+-\frac{168}{30}+\frac{186}{30}\right).\frac{7}{8}\)\(=\frac{29}{3}.\frac{7}{8}=\frac{203}{24}\)
a) \(\left(\frac{9}{10}-\frac{15}{16}\right).\left(\frac{5}{12}-\frac{11}{15}-\frac{7}{20}\right)\)
B) \(\frac{-3}{5}+\frac{28}{5}.\left(\frac{43}{56}+\frac{5}{24}-\frac{21}{63}\right)\)
thực hiện phép tính
Tính nhanh :
\(\left(1-\frac{1}{3}\right).\left(1-\frac{1}{6}\right).\left(1-\frac{1}{10}\right).\left(1-\frac{1}{15}\right).\left(1-\frac{1}{21}\right).\left(1-\frac{1}{28}\right)\)
=2/3.5/6.9/10.14/15.20/21.27/28
=5/9.21/15.45/49
=7/9.45/49
=5/7
hơi dài dòng nhưng mong bạn tích đúng cho mk nha
1. Tìm x thuộc Z biết:
a,\(\frac{-5}{6}.\frac{120}{25}< x< \frac{-7}{15}.\frac{9}{14}\)
b,\(\left(\frac{-5}{3}\right)^3< x< \frac{-24}{35}.\frac{-5}{6}\)
2. Thực hiện phép tính:
a,\(\left(\frac{9}{10}-\frac{15}{16}\right).\left(\frac{5}{12}-\frac{11}{15}-\frac{7}{20}\right)\)
b,\(\frac{-3}{5}+\frac{28}{5}.\left(\frac{43}{56}+\frac{5}{24}-\frac{21}{63}\right)\)
AI GIÚP MIK VỚI,MIK DÂNG CẦN GẤP,SÁNG MAI MIK PHẢI NỘP CHO CÔ RỒI,GIÚP MIK NHA
1)
a)
\(\frac{-5}{6}.\frac{120}{25}< x< \frac{-7}{15}.\frac{9}{14}\)
\(\frac{-1}{1}.\frac{20}{5}< x< \frac{-1}{5}.\frac{3}{2}\)
\(\frac{-20}{5}< x< \frac{-3}{10}\)
\(\frac{-40}{10}< x< \frac{-3}{10}\)
\(\Rightarrow Z\in\left\{-4;-5;-6;-7;-8;-9;-10;...;-39\right\}\)
\(\left(\frac{-5}{3}\right)^3< x< \frac{-24}{35}.\frac{-5}{6}\)
\(\frac{25}{3}< x< \frac{-4}{7}.\frac{1}{1}\)
\(\frac{-25}{3}< x< \frac{-4}{7}\)
\(\frac{-175}{21}< x< \frac{-12}{21}\)
\(\Rightarrow Z\in\left\{-13;-14;-15;-16;...;-174\right\}\)
2)
a)
\(\left(\frac{9}{10}-\frac{15}{16}\right).\left(\frac{5}{12}-\frac{11}{15}-\frac{7}{20}\right)\)
\(=\left(\frac{72}{80}-\frac{75}{80}\right).\left(\frac{25}{60}-\frac{44}{60}-\frac{21}{60}\right)\)
\(=\frac{-3}{80}.\frac{-40}{60}\)
\(=\frac{-1}{-2}.\frac{-1}{-20}\)
\(=\frac{1}{40}\)
1,tính nhanh:
A=\(\frac{8^{19}+1}{8^{20}+1}\)và B=\(\frac{8^{20}-1}{8^{20}-3}\)
2, tìm n thuộc z để:
A=\(\frac{n^2+1}{n^2-3}\)
3, tính bằng cách hợp lí:
B=(\(\frac{136}{15}\)-\(\frac{28}{5}\)+\(\frac{62}{10}\)) . \(\frac{21}{24}\)
GIÚP MIK VS CÁC BẠN ƠI :))
bài 1 ; thực hiện phép tính (tính nhanh nếu có thể)
a) \(\left(\frac{-1}{4}+\frac{7}{33}-\frac{5}{3}\right)-\left(\frac{-15}{12}+\frac{6}{11}-\frac{48}{49}\right)\)
b) \(\frac{3}{14}:\frac{1}{28}-\frac{13}{21}:\frac{1}{28}+\frac{29}{42}:\frac{1}{28}-8\)
\(\left(\frac{-1}{4}+\frac{7}{33}-\frac{5}{3}\right)-\left(\frac{-5}{4}+\frac{6}{11}-\frac{48}{49}\right)=\left(\frac{-1}{4}-\frac{16}{11}\right)-\left(-\frac{31}{44}-\frac{48}{49}\right)=-\frac{1}{4}-\frac{16}{11}+\frac{31}{44}+\frac{48}{49}=-\frac{1}{49}\)