\(a)22.3-\left(110+7\right):326\)

\(=66-117:326\)

\(=66-\frac{117}{326}\)

\(=\frac{21399}{326}\)

\(b)1+2+3+.....+2019+2010\)

Ta tạm để số 2010 ra ngoài .

Số số hạng của tổng trên là :

( 2019 - 1 ) : 1 + 1 = 2019 ( sh )

Tổng trên là :

\(\left(2019+1\right)\times2019:2=2039190\)

\(\Rightarrow2039190+2010=2041200\)

\(c)64:4+2.52\)

\(=16+104\)

\(=120\)

\(d)2008.213+87.2008\)

\(=2008.\left(213+87\right)\)

\(=2008.300\)

\(=602400\)

\(e)12: \left\{390:\left[500-\left(125+35.7\right)\right]\right\}\)

\(=12:\left\{390:\left[500-370\right]\right\}\)

\(=12:\left\{390:130\right\}\)

\(=12:3=4\)

\(g)33.118-33.18\)

\(=3894-594\)

\(=3300\)

\(h)150-\left[102-\left(14-11\right).2\right]:9\)

\(=150-\left[102-6\right]:9\)

\(=150-96:9\)

\(=150-\frac{32}{33}\)

\(=\frac{4918}{33}\)

\(i)4.52-3\)

\(=208-3\)

\(=205\)

\(a,\left(48\cdot0,75-240:10\right)-\left(16\cdot0,5-16:4\right)\)

\(=\left(48\cdot0,75-240\cdot0,1\right)-\left(16:2-16:4\right)\)

\(=\left(36-24\right)-\left(8-4\right)\)

\(=12-4=8\)

\(b,\left(\frac{1}{2}+\frac{3}{5}-\frac{2}{15}\right):\frac{3}{5}\)

\(=\left(\frac{11}{10}-\frac{2}{15}\right):\frac{3}{5}\)

\(=\frac{29}{30}:\frac{3}{5}=\frac{145}{90}=\frac{29}{18}\)

\(c,\left(\frac{13}{84}\cdot\frac{2}{5}-\frac{1}{2}\cdot\frac{7}{180}\right):\frac{27}{18}+\frac{1}{2}\cdot\frac{1}{10}\)

\(=\left(\frac{26}{420}-\frac{7}{360}\right):\frac{3}{2}+\frac{1}{20}\)

\(=\left(\frac{13}{210}-\frac{7}{360}\right):\frac{3}{2}+\frac{1}{20}\)

\(=\frac{107}{2520}:\frac{3}{2}+\frac{1}{20}\)

\(=\frac{214}{7560}+\frac{1}{20}=\frac{214}{7560}+\frac{378}{7560}\)

\(=\frac{592}{7560}=\frac{74}{945}\)

Trả lời:

a, \(\left(48\times0,75-240\div10\right)-\left(16\times0,5-16\div4\right)\)

\(=\left(36-24\right)-\left(8-4\right)\)

\(=12-4\)

\(=8\)

b,\(\left(\frac{1}{2}+\frac{3}{5}-\frac{2}{15}\right)\div\frac{3}{5}\)

\(=\left(\frac{11}{10}-\frac{2}{15}\right)\times\frac{5}{3}\)

\(=\frac{29}{30}\times\frac{5}{3}\)

\(=\frac{29}{18}\)

c,\(\left(\frac{13}{84}\times\frac{2}{5}-\frac{1}{2}\times\frac{7}{180}\right)\div\frac{27}{18}+\frac{1}{2}\times\frac{1}{10}\)

\(=\left(\frac{13}{210}-\frac{7}{360}\right)\times\frac{18}{27}+\frac{1}{2}\times\frac{1}{10}\)

\(=\frac{107}{2520}\times\frac{18}{27}+\frac{1}{20}\)

\(=\frac{107}{3780}+\frac{1}{20}\)

\(=\frac{74}{945}\)

\(\left(a\right)2,52:0,56\cdot7,2:2,5\)

\(=4,5\cdot7,2:2,5\)

\(=32,4:2,5=12,96\)

\(\left(b\right)4,36+13,734:13,08-2,716\)

\(=4,36+1,05-2,716\)

\(=5,41-2,716=2,694\)

\(\left(c\right)\frac{5}{13}\cdot\left(\frac{5}{20}-\frac{1}{10}\right)+\frac{2}{5}\)

\(=\frac{5}{13}\cdot\left(\frac{5}{20}-\frac{2}{20}\right)+\frac{2}{5}\)

\(=\frac{5}{13}\cdot\frac{3}{20}+\frac{2}{5}\)

\(=\frac{15}{260}+\frac{2}{5}=\frac{15}{260}+\frac{104}{260}\)

\(=\frac{119}{260}\)

Trả lời:

a, \(2,52\div0,56\times7,2\div2,5\)

\(=4,5\times7,2\div2,5\)

\(=32,4\div2,5\)

\(=12,96\)

b,\(4,36+13,734\div13,08-2,716\)

\(=4,36+1,05-2,716\)

\(=5,41-2,716\)

\(=2,694\)

c,\(\frac{5}{13}\times\left(\frac{5}{20}-\frac{1}{10}\right)+\frac{2}{5}\)

\(=\frac{5}{13}\times\frac{3}{20}+\frac{2}{5}\)

\(=\frac{3}{52}+\frac{2}{5}\)

\(=\frac{119}{260}\)

Viet Nam is in the Soul - East Asia . It has lots of beautiful mountains rivers and beaches . There are tow long river the mekong rivers is the south rive in the soul east asia and of couse it is longer than the red rivers . The mekong river starts in tibet and flows into to the bien dong phanxipang is the hingest mountian in Viet Nam . It 3,14 meters Viet Nam aslo has many nice beaches such as Sam Son , Nha Trang , Vung tau .

Học tốt

1. lots

2. there

3. river

4. south

5. longest

6. than

7. flows into

8. the 

9. heigh

10. has

j) \(\frac{8}{3}.\frac{2}{5}.\frac{3}{8}.10.\frac{19}{92}=\left(\frac{8}{3}.\frac{3}{8}\right).\left(\frac{2}{5}.10\right).\frac{19}{92}=1.4.\frac{19}{92}\)

\(=\frac{19}{23}\)

k)\(\frac{-5}{7}.\frac{2}{11}.\frac{-13}{17}.\frac{19}{12}.\frac{17}{13}=\left(\frac{2}{11}.\frac{19}{12}\right).\left(\frac{-13}{17}.\frac{17}{13}\right).\frac{-5}{7}\)

\(=\frac{-19}{66}.\frac{-5}{7}=\frac{95}{462}\)

l)\(\frac{12}{19}.\frac{7}{15}.\frac{-13}{17}.\frac{19}{12}.\frac{17}{13}=\left(\frac{12}{19}.\frac{19}{12}\right).\left(\frac{-13}{17}.\frac{17}{13}\right).\frac{7}{15}\)

\(=\frac{-7}{15}\)

cậu tham khảo trên này ạ, nếu đúng cho mk 1 t.i.c.k ạ, thank nhiều

e. \(\frac{-3}{5}\cdot\frac{5}{7}+\frac{-3}{5}\cdot\frac{3}{7}+\frac{-3}{5}\cdot\frac{6}{7}=-\frac{3}{5}\left(\frac{5}{7}+\frac{3}{7}+\frac{6}{7}\right)=-\frac{3}{5}\cdot2=-\frac{6}{5}\)

f. \(\frac{1}{3}\cdot\frac{4}{5}+\frac{1}{3}\cdot\frac{6}{5}-\frac{4}{5}=\frac{1}{3}\left(\frac{4}{5}+\frac{6}{5}\right)-\frac{4}{5}=\frac{1}{3}\cdot2-\frac{4}{5}=\frac{2}{3}-\frac{4}{5}=-\frac{2}{15}\)

g. \(\frac{4}{19}\cdot\frac{-3}{7}+\frac{-3}{7}\cdot\frac{15}{19}+\frac{5}{7}=-\frac{3}{7}\left(\frac{4}{19}+\frac{15}{19}\right)+\frac{5}{7}=-\frac{3}{7}\cdot1+\frac{5}{7}=-\frac{3}{7}+\frac{5}{7}=\frac{2}{7}\)

h. \(\frac{5}{9}\cdot\frac{7}{13}+\frac{5}{9}\cdot\frac{9}{13}-\frac{5}{9}\cdot\frac{3}{13}=\frac{5}{9}\left(\frac{7}{13}+\frac{9}{13}-\frac{3}{13}\right)=\frac{5}{9}\cdot1=\frac{5}{9}\)

a) \(2x^2-72=0\)

\(\Leftrightarrow2\left(x^2-36\right)=0\Leftrightarrow x^2-36=0\Leftrightarrow x=_-+6\)

\(2x^2-72=0\)

\(\Leftrightarrow2x^2=72\)

\(\Leftrightarrow x^2=36\)

\(\Leftrightarrow x=\sqrt{36}=6\)

b) số xấu

\(\left[\frac{3}{4}-x\right]^3=-8\)

\(\Leftrightarrow\left[\frac{3}{4}-x\right]^3=\left(-2\right)^3\)

\(\Leftrightarrow\frac{3}{4}-x=-2\)

\(\Leftrightarrow x=\frac{3}{4}-\left(-2\right)\)

\(\Leftrightarrow x=\frac{3}{4}+2=\frac{3}{4}+\frac{8}{4}=\frac{11}{4}\)

\(\frac{7256\cdot4375-725}{3650+4375\cdot7255}=\frac{\left(7255+1\right)\cdot4375-725}{3650+4375\cdot7255}\)

\(=\frac{7255\cdot4375+4375-725}{3650+4375\cdot7255}=\frac{7255\cdot4375+3650}{3650+4375\cdot7255}\)

\(\frac{7255\cdot4375+3650}{7255\cdot4375+3650}=1\)

=(7255+1)x4375-725 / 3650+4375x7255

=4375x7255+4375-725 / 3650+4375x7255

=4375x7255+3650 / 4375x7255+3650

=1