a) A = \(\frac{101}{19}.\) \(\frac{61}{218}-\frac{101}{218}.\frac{42}{19}+\frac{117}{218}\)

        = \(\frac{101}{218}.\frac{61}{19}-\frac{101}{218}.\frac{42}{19}+\frac{117}{218}\)

        =\(\frac{101}{218}.\left(\frac{61}{19}-\frac{42}{19}\right)+\frac{117}{218}\)

        =\(\frac{101}{218}.\frac{19}{19}+\frac{117}{218}\)

        =\(\frac{101}{218}.1+\frac{117}{218}\)

        =\(\frac{101}{218}+\frac{117}{218}\)

        =\(\frac{218}{218}\)\(=1\)

b) B = \(\left(\frac{5}{2011^2}+\frac{7}{2012^2}-\frac{9}{2013^2}\right).\left(\frac{4}{5}-\frac{3}{4}-\frac{1}{20}\right)\)

        =     \(\left(\frac{5}{2011^2}+\frac{7}{2012^2}-\frac{9}{2013^2}\right)\)\(.\left(\frac{1}{20}-\frac{1}{20}\right)\)

        = \(\left(\frac{5}{2011^2}+\frac{7}{2012^2}-\frac{9}{2013^2}\right).0\)

        = \(0\)

\(\frac{-3}{14}\) - \(\frac{5}{-14}\)

= \(\frac{-3}{14}+\frac{5}{14}\)

= \(\frac{2}{14}\)

= \(\frac17\)

- \(\frac54\) - \(\frac34\)

= -(\(\frac54+\frac34\))

= - \(\frac84\)

= - 2

\(\frac{15}{6}-\frac{-10}{20}\)

= \(\frac52\) + \(\frac12\)

= \(\frac62\)

= 3

\(\frac{26}{-35}\) - \(\frac{6}{35}\)

= - (\(\frac{26}{35}\) + \(\frac{6}{35}\))

=- \(\frac{32}{35}\)

a) \(22\frac{1}{2}\cdot\frac{7}{9}+50\%-1,25\)

\(=\frac{45}{2}\cdot\frac{7}{9}+\frac{50}{100}-\frac{125}{100}\)

\(=\frac{5}{2}\cdot\frac{7}{1}+\frac{1}{2}-\frac{5}{4}\)

\(=\frac{35}{2}+\frac{1}{2}-\frac{5}{4}=18-\frac{5}{4}=\frac{67}{4}\)

b) \(1,4\cdot\frac{15}{49}-\left(\frac{4}{5}+\frac{2}{3}\right):2\frac{1}{5}\)

\(=\frac{7}{5}\cdot\frac{15}{49}-\frac{22}{15}:\frac{11}{15}\)

\(=\frac{1}{1}\cdot\frac{3}{7}-\frac{22}{15}\cdot\frac{15}{11}\)

\(=\frac{3}{7}-2=\frac{3-14}{7}=\frac{-11}{7}\)

c) \(\left(-\frac{1}{2}\right)^2-\frac{7}{16}:\frac{7}{4}+75\%\)

\(=\frac{1}{4}-\frac{7}{16}\cdot\frac{4}{7}+\frac{75}{100}\)

\(=\frac{1}{4}-\frac{1}{4}+\frac{3}{4}=\frac{3}{4}\)

Bài 2  Bạn tự làm nhé

1.a,\(22\frac{1}{2}.\frac{7}{9}+50\%-1,25\)

\(=\frac{45}{2}.\frac{7}{9}+\frac{1}{2}-\frac{5}{4}\)

\(=\frac{35}{2}+\frac{1}{2}-\frac{5}{4}\)

\(=\frac{67}{4}\)

b,Các phép tính khác làm tương tự

Đổi các số ra hết thành phân số,có ngoặc thì lm ngoặc trc,Xoq đến nhân chia trước dồi mới cộng trừ

c,tương tự

2.

a,\(1\frac{3}{5}+\frac{7}{12}\div x=\frac{-9}{4}\)

\(\frac{8}{5}+\frac{7}{12}\div x=\frac{-9}{4}\)

\(\frac{7}{12}\div x=\frac{-77}{20}\)

Đến đây dễ bạn tự làm

b,\(\left(2\frac{4}{5}.x+50\right)\div\frac{2}{3}=-51\)

\(\left(\frac{14}{5}x+50\right)\div\frac{2}{3}=-51\)

\(\frac{14}{5}x+50=-34\)

\(\frac{14}{5}x=-84\)

Tự làm tiếp

c,\(\left|\frac{3}{4}.x-\frac{1}{2}\right|=\frac{1}{4}\)\(\Rightarrow\left|\frac{3}{4}x-\frac{1}{2}\right|=\varnothing\)

a) \(\frac{1}{3}-\frac{-1}{6}=\frac{1}{3}+\frac{1}{6}=\frac{1}{2}\)

b) \(2\frac{1}{3}+4\frac{1}{5}=\frac{7}{3}+\frac{21}{5}=\frac{98}{15}\)

c) \(\frac{4}{9}-\frac{13}{3}-\frac{4}{9}-\frac{10}{3}=\left(\frac{4}{9}-\frac{4}{9}\right)-\left(\frac{13}{3}+\frac{10}{3}\right)\)

\(=0-\frac{23}{3}=\frac{-23}{3}\)

d) \(4-\left(2-\frac{5}{2}\right)+0,5=4-2+\frac{5}{2}+\frac{1}{2}=2+3=5\)

a,=4¹⁰

b,=3¹⁶

c,=3ⁿ

d,=10¹⁶

e,=...

a) \(16^6:4^2=\left(4^2\right)^6:4^2=4^{12}:4^2=4^{10}\)

b) \(27^8:9^4=\left(3^3\right)^8:\left(3^2\right)^4=3^{24}:3^8=3^{16}\)

c) \(12^n:2^{2n}=12^n:4^n=3^n\)

d) \(4^{14}\times5^{18}=\left(4^7\right)^2\times\left(5^9\right)^2=\left(4^7\times5^9\right)^2\)

giúp mik với mik cần gấp mai mik phải nộp cho cô

very important !!!!!!

a,-3/5.2/7+-3/7.3/5+-3/7

=-3/7.2/5+(-3/7).3/5+(-3/7) 

=-3/7(2/5+3/5+1)

=-3/7.2

=-6/7

\(\left(3x-1\right)⋮\left(x+1\right)\)

\(\Rightarrow\left(3x+3-4\right)⋮\left(x+1\right)\)

\(\Rightarrow\left(-4\right)⋮\left(x+1\right)\)

\(\Rightarrow x+1\inƯ\left(-4\right)=\left\{-4;-1;1;4\right\}\)

\(\Rightarrow x\in\left\{-5;-2;0;3\right\}\)

a, ĐỂ \(\frac{24}{2n+5}\)là số nguyên 

\(\Rightarrow24⋮2n+5\Rightarrow2n+5\inƯ\left(24\right)=\left\{\pm1;\pm2;\pm3;\pm4;\pm6;\pm8;\pm12;\pm24\right\}\)

2n + 5 = 1 => 2n = -4 => n = -2 

2n + 5 = -1 => n = -3 

... tương tự thay vào nhé !