TÔI KHÔNG THỐNG NHẤT

kết quả là 241fac

\((\dfrac{7}{11}+\dfrac{4}{11}+(\dfrac{5}{6}+\dfrac{1}{6})=1-1=0\)

\(\frac{7}{11}+\frac{5}{6}-\frac{-4}{11}-\frac{1}{6} \)

\(=\frac{7}{11}+\frac{5}{6}+\frac{4}{11}+\frac{-1}{6}\)

\(=\left(\frac{7}{11}+\frac{4}{11}\right)+\left(\frac{5}{6}+\frac{-1}{6}\right)\)

\(=\frac{11}{11}+\frac{4}{6}\)

\(=1+\frac{2}{3}\)

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

\(=\frac{5}{3}\)

Bài 1:

a) \(\frac{-5}{21}+\frac{-2}{21}+\frac{8}{24} \)

\(=\frac{-7}{21}+\frac{1}{3}\)

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

\(=0\)

b) \(\frac{-3}{5}.\frac{2}{7}+\frac{-3}{5}.\frac{5}{7}+2\frac{3}{5}\)

\(=\frac{-3}{5}.\left(\frac{2}{7}+\frac{5}{7}\right)+\frac{13}{5}\)

\(=\frac{-3}{5}.1+\frac{13}{5}\)

\(=\frac{-3}{5}+\frac{13}{5}\)

\(=\frac{10}{5}\)

\(=2\)

c) \(75\%-1\frac{1}{2}+0,5\div\frac{5}{12}-\left(-\frac{1}{2}\right)^2\)

\(=\frac{3}{4}-\frac{3}{2}+\frac{1}{2}.\frac{12}{5}-\frac{1}{4}\)

\(=\frac{3}{4}-\frac{3}{2}+\frac{6}{5}-\frac{1}{4}\)

\(=\frac{3}{4}+\frac{-3}{2}+\frac{6}{5}+\frac{-1}{4}\)

\(=\left(\frac{3}{4}+\frac{-1}{4}\right)+\frac{-3}{2}+\frac{6}{5}\)

\(=\frac{1}{2}+\frac{-3}{2}+\frac{6}{5}\)

\(=-1+\frac{6}{5}\)

\(=\frac{-5}{5}+\frac{6}{5}\)

\(=\frac{1}{5}\)

Bài 2:

a) \(1\frac{1}{3}+\frac{2}{3}x=5\frac{1}{3}\)

\(\frac{4}{3}+\frac{2}{3}x=\frac{16}{3}\)

\(\frac{2}{3}x=\frac{16}{3}-\frac{4}{3}\)

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

\(x=4\div\frac{2}{3}\)

\(x=4.\frac{3}{2}\)

\(x=6\)

Vậy \(x=6\)

b) \(\left(x+\frac{1}{3}\right)\left(\frac{3}{4}-2x\right)=0\)

TH1: \(x+\frac{1}{3}=0\)

\(x=0-\frac{1}{3}\)

\(x=\frac{-1}{3}\)

TH2 : \(\frac{3}{4}-2x=0\)

\(2x=\frac{3}{4}-0\)

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

\(x=\frac{3}{4}\div2\)

\(x=\frac{3}{4}.\frac{1}{2}\)

\(x=\frac{3}{8}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{-1}{3}\\x=\frac{3}{8}\end{cases}}\)

c) \(\frac{-4}{5}x+1\frac{1}{3}x=-1\frac{1}{3}\)

\(\frac{-4}{5}x+\frac{4}{3}x=\frac{-4}{3}\)

\(\left(\frac{-4}{5}+\frac{4}{3}\right).x=\frac{-4}{3}\)

\(\frac{8}{15}.x=\frac{-4}{3}\)

\(x=\frac{-4}{3}\div\frac{8}{15}\)

\(x=\frac{-4}{3}.\frac{15}{8}\)

\(x=\frac{-5}{2}\)

Vậy \(x=\frac{-5}{2}\)

`Answer:`

Có số số hạng từ `1` đến `9` là: `9-1+1=9` số hạng

`=>1+2+3+...+9=(9+1).9:2=45`

Có số số hạng từ `11` đến `19` là: `19-11+1=9` số hạng

`=>11+12+13+...+19=(19+11).9:2=135`

`=>A=45/135=1/3`

Câu 1:

10 000 000 000 000 000 000 000+1=10 000 000 000 000 000 000 001.

Chúc học tốt!

10000000000000000000001 nhóa :3