\(\dfrac{9x}{2}-\dfrac{13x}{4}=1\)

\(\dfrac{18x-13x}{4}=1\)

\(5x=4\)

\(x=\dfrac{4}{5}\)

`3/4 + 5/6 = 9/12 + 10/12 = 19/12`

`1/2 + 7/12 = 6/12 + 7/12 = 13/12`

`2/3 xx 3/4 = 2/4 = 1/2`

`7/4 : 2 = 7/4 xx 1/2 = 7/8`

\(a,\dfrac{3}{4}+\dfrac{5}{6}=\dfrac{18}{24}+\dfrac{20}{24}=\dfrac{38}{24}=\dfrac{19}{12}\)

\(b,\dfrac{1}{2}+\dfrac{7}{12}=\dfrac{6}{12}+\dfrac{7}{12}=\dfrac{13}{12}\)

\(c,\dfrac{2}{3}x\dfrac{3}{4}=\dfrac{2}{4}\)

\(d,\dfrac{7}{4}:2=\dfrac{7}{4}x\dfrac{1}{2}=\dfrac{7}{8}\)

\(a,\dfrac{7}{12}+\dfrac{3}{4}\times\dfrac{2}{9}=\dfrac{7}{12}+\dfrac{1}{6}=\dfrac{7}{12}+\dfrac{2}{12}=\dfrac{9}{12}=\dfrac{3}{4}\)

\(b,\dfrac{8}{9}-\dfrac{4}{15}:\dfrac{2}{5}=\dfrac{8}{9}-\dfrac{4}{15}\times\dfrac{5}{2}=\dfrac{8}{9}-\dfrac{2}{3}=\dfrac{8}{9}-\dfrac{6}{9}=\dfrac{2}{9}\)

đùa thì kệ con mẹ mày xàm loz

Đáp án a là 0,75 

Đáp án b: là 0.86222222222

Bạn xem kỹ lại đề có đúng không?

Ta có: \(\left(\dfrac{1}{2}x+\dfrac{3}{4}\right)^2=\dfrac{1}{16}\)

\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x+\dfrac{3}{4}=\dfrac{-1}{4}\\\dfrac{1}{2}x+\dfrac{3}{4}=\dfrac{1}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x=-1\\\dfrac{1}{2}x=\dfrac{-1}{2}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=1\end{matrix}\right.\)

`(x/2 + 3/4)^2 = 1/16`

`=> (x/2 + 3/4)^2 = (1/4)^2`

Xét `x/2 + 3/4 = 1/4`

`=> x/2 = 1`

`=> x = 2`

Xét `x/2 + 3/4 = -1/4`

`=> x/2 = 1/2`

`=> x = 1`

Vậy `x = 1;2`

(Chúc bạn học tốt)

\(\left(\dfrac{x}{2}+\dfrac{3}{4}\right)^2=\dfrac{1}{16}\)

theo dõi giúp mik nhé^^

a: Ta có: \(\dfrac{2}{\sqrt{3}+1}+\dfrac{2}{2-\sqrt{3}}\)

\(=\sqrt{3}-1+2+\sqrt{3}\)

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

b: Ta có: \(\dfrac{4}{\sqrt{5}+2}+\dfrac{2}{3+\sqrt{5}}\)

\(=4\sqrt{5}-8+\dfrac{3}{2}-\dfrac{\sqrt{5}}{2}\)

\(=-\dfrac{13}{2}+\dfrac{7}{2}\sqrt{5}\)

Giải j bn

\(WTF^3\)

\(-\dfrac{2}{3}\left(\dfrac{3}{2}-x\right)=\dfrac{3}{4}\left(\dfrac{1}{6}-\dfrac{2}{9}\right)\)

\(< =>-1+\dfrac{2x}{3}=\dfrac{3}{4}\left(\dfrac{3-4}{18}\right)< =>-1+\dfrac{2x}{3}=\dfrac{3}{4}.\dfrac{-1}{18}\)

\(< =>-1+\dfrac{2x}{3}=-\dfrac{1}{24}=>\dfrac{2x}{3}=-\dfrac{1}{24}+1\)

\(< =>\dfrac{2x}{3}=\dfrac{23}{24}=>48x=69=>x=\dfrac{69}{48}=\dfrac{23}{16}\)

\(C=\dfrac{-5}{7}+\dfrac{-2}{7}+\dfrac{3}{4}+\dfrac{1}{4}+\dfrac{-1}{5}=-1+1-\dfrac{1}{5}=\dfrac{-1}{5}\)