Tính bằng cách thuận tiện
a) \(\frac{5}{11}x\frac{7}{25}+\frac{15}{11}x\frac{1}{5}\)
b) \(\frac{3}{7}x\frac{25}{19}-\frac{1}{7}x\frac{18}{19}\)
tính bằng cách thuận tiện\(\frac{3}{7}x\frac{25}{19}-\frac{1}{7}x\frac{18}{19}\)
Uk, vậy cái dấu gì ở giữa chữ x và số 25/19 vậy bạn?? ^ ^
Bai 1: a) \(\frac{3}{7}.\frac{-5}{9}+\frac{4}{9}.\frac{3}{7}-\frac{3}{7}.\frac{8}{9}\)
b) \(1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right):\frac{7}{5}\)
bài 2:
a) \(\frac{-3}{4}x-\frac{4}{10}=\frac{1}{5}\)
b) \(3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{19}:\frac{12}{19}\)
c)
\(bai1:a,\frac{3}{7}\cdot\frac{-5}{9}+\frac{4}{9}\cdot\frac{3}{7}-\frac{3}{7}\cdot\frac{8}{9}\)
\(< =>\frac{-15}{63}+\frac{12}{63}-\frac{24}{63}\)
\(< =>\frac{-15+12-24}{63}\)
\(< =>\frac{-3}{7}\)
\(b,1\frac{13}{15}\cdot0,75-\left(\frac{11}{20}+25\%\right):\frac{7}{5}\)
\(< =>\frac{28}{15}\cdot\frac{3}{4}-\left(\frac{11}{20}+\frac{1}{4}\right):\frac{7}{5}\)
\(< =>\frac{7}{5}-\frac{4}{5}:\frac{7}{5}\)
\(< =>\frac{7}{5}-\frac{4}{7}\)
\(< =>\frac{29}{35}\)
\(bai2:\)
\(a,\frac{-3}{4}\cdot x-\frac{4}{10}=\frac{1}{5}\)
\(< =>\frac{-3}{4}\cdot x=\frac{1}{5}+\frac{4}{10}\)
\(< =>\frac{-3}{4}\cdot x=\frac{3}{5}\)
\(< =>x=\frac{3}{5}:\frac{-3}{4}\)
\(< =>x=\frac{-4}{5}\)
\(b,3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{19}:\frac{12}{19}\)
\(< =>3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{12}\)
\(< =>\left[3\left(x-\frac{1}{3}\right)\right]=\frac{1}{12}< =>x-\frac{1}{3}=\frac{1}{12}:3=\frac{1}{36}=>x=\frac{1}{36}+\frac{1}{3}=>x=\frac{13}{36}\)
\(< =>\left[\frac{1}{3}\cdot x\right]=\frac{1}{12}< =>x=\frac{1}{12}:\frac{1}{3}=>x=\frac{1}{4}\)
Bài 1:
a)\(\frac{3}{7}.\frac{-5}{9}+\frac{4}{9}.\frac{3}{7}-\frac{3}{7}.\frac{8}{9}\) b,\(1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right):\frac{7}{5}\)
\(=\frac{3}{7}.(\frac{-5}{9}+\frac{4}{9}-\frac{8}{9})\) \(=\frac{28}{15}.\frac{3}{4}-\left(\frac{11}{20}+\frac{5}{20}\right):\frac{7}{5}\)
\(=\frac{3}{7}.\frac{-9}{9}\) \(=\frac{7}{5}-\frac{4}{5}:\frac{7}{5}\)
\(=\frac{-3}{7}\) \(=\frac{7}{5}-\frac{4}{7}\)
\(=\frac{29}{35}\)
Bài 2:
a)\(\frac{-3}{4}x-\frac{4}{10}=\frac{1}{5}\) b,\(3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{19}:\frac{12}{19}\)
\(\frac{-3}{4}x\) \(=\frac{1}{5}+\frac{4}{10}\) \(3\left(x-\frac{1}{3}\right)+\frac{1}{3}x=\frac{1}{12}\)
\(\frac{-3}{4}x\) \(=\frac{3}{5}\) \(\left(x.3-\frac{1}{3}.3\right)+\frac{1}{3}x=\frac{1}{12}\)
\(x\) \(=\frac{3}{5}:\frac{-3}{4}\) \(\left(x.3-1\right)+\frac{1}{3}x=\frac{1}{12}\)
\(x\) \(=\frac{4}{-5}\) \(x.\left(3+\frac{1}{3}\right)-1=\frac{1}{12}\)
\(x.\left(3+\frac{1}{3}\right)=\frac{1}{12}+1\)
\(x.\frac{10}{3}=\frac{13}{12}\)
\(x=\frac{13}{12}:\frac{10}{3}\)
\(x=\frac{13}{40}\)
tính nhanh
a) \(\frac{3}{11}\)x \(\frac{7}{25}\)+ \(\frac{15}{11}\)x \(\frac{1}{5}\)
b) \(\frac{3}{7}\)x \(\frac{25}{19}\)+ \(\frac{1}{7}\)x \(\frac{18}{19}\)
c) \(\frac{6}{7}\)x \(\frac{3}{8}\)+ \(\frac{6}{7}\): \(\frac{8}{5}\)+ \(\frac{6}{7}\)
giải giúp e với e cảm ơn ạ
Tính giá trị các biểu thức sau một cách nhanh nhất:
a) 0.2 x 517 x 7 x 0.7 x 483 x 2
b) \(\frac{4}{9}+\frac{6}{11}+\frac{5}{9}+\frac{16}{11}+7\)
c) \(\frac{3}{5}+\frac{5}{1}+\frac{7}{13}+\frac{2}{5}+\frac{16}{11}+\frac{19}{13}\)
Câu 1: Thực hiện phép tính bằng cách hợp lí
\(\frac{15}{35}+\frac{7}{21}+\frac{19}{34}-1\frac{15}{17}+\frac{2}{3}\)
\(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)
\(16\frac{2}{7}:\left(-\frac{3}{5}\right)+28\frac{2}{7}:\left(-\frac{3}{5}\right)\)
Câu 2: Tìm x biết
\(2.x-\frac{5}{4}=\frac{20}{15}\)
\(1,5:0,3=x:-15\)
\(|2x-1|=2\)
Câu 3: Thực hiện phép tính hợp lí
\(\frac{11}{12}.\frac{15}{33}+\frac{11}{12}.\frac{2}{22}\)
\(3/3\frac{1}{8}.11\frac{17}{19}-3\frac{1}{8}.13\frac{17}{19}\)
\(28\frac{2}{7}:\left(-\frac{3}{5}\right)+16\frac{2}{7}:\left(-\frac{3}{5}\right)\)
Giải phương trình:
a)\(\frac{x+81}{19}+\frac{x+82}{18}=\frac{x+84}{16}+\frac{x+85}{15}\)
b)\(\frac{x-22}{8}+\frac{x-21}{9}+\frac{x-20}{10}+\frac{x-19}{11}=4\)
c)\(\frac{x+19}{3}+\frac{x+13}{5}=\frac{x+7}{7}+\frac{x+1}{9}\)
d)\(\frac{2-x}{2018}-1=\frac{1-x}{2019}-\frac{x}{2020}\)
Tính bằng cách thuận tiện nhất .
\(\frac{39}{16}:\frac{5}{8}-\frac{17}{16}:\frac{5}{18}+\frac{4}{5}\)
\(\frac{16}{17}x\frac{12}{19}+\frac{16}{17}x\frac{7}{19}-\frac{2}{3}\)
Trả lời
Sửa đề câu a 1 tí
a)39/16:5/8-17/16:5/8+4/5
=(39/16-17/16):5/8+4/5
=11/8:5/8+4/5
=11/5+4/5
=15/5=3
b)16/17.12/19+16/17.7/19-2/3
=16/17.(12/19+7/19)-2/3
=16/17-2/3
=48/56-14/56
=34/56=17/28
Học tốt !
Tính
\(1\frac{5}{7}-\frac{5}{7}.\frac{2}{11}-\frac{5}{7}.\frac{9}{11}\)
\(\frac{3}{11}.\frac{7}{19}.\frac{17}{11}.\frac{3}{9}-\frac{3}{19}.\frac{15}{11}\)
\(\frac{5}{11}.\frac{18}{29}-\frac{5}{11}.\frac{8}{29}+\frac{5}{11}.\frac{19}{26}\)
\(\frac{17}{23}.\frac{8}{16}.\frac{27}{17}.80.\frac{3}{4}\)
\(\left(\frac{13}{23}+\frac{1313}{2323}-\frac{131313}{232323}\right).\left(\frac{1}{3}+\frac{1}{4}-\frac{7}{12}\right)\)
Giải giùm mk zới mn~~~~tặng người đầu tiên làm 4 tick nha(đảm bảo lên 4 điểm 100%)
a)\(\frac{-4}{9}.\frac{7}{15}+\frac{4}{-9}.\frac{8}{15}\)
b)\(\frac{5}{-4}.\frac{16}{25}+\frac{-5}{4}.\frac{9}{25}.\)
c)\(4\frac{11}{23}-\frac{9}{14}+2\frac{12}{23}-\frac{5}{4}.\)
d)\(2\frac{13}{27}-\frac{7}{15}+3\frac{14}{27}-\frac{8}{15}\)
e)\(11\frac{1}{4}-\left\{2\frac{5}{7}+5\frac{1}{4}\right\}\)
g)\(\frac{7}{19}.\frac{8}{11}+\frac{7}{19}.\frac{3}{11}+\frac{12}{19}\)
â, -4/9(7/15+8/15)=-4/9
b,-5/4(16/25+9/25)=-5/4
,.....
dài quá mik làm ko hết
hok tốt