`x-2/3=3/4`

`=>x=3/4 + 2/3`

`=> x= 9/12 + 8/12`

`=>x= 17/12`

\(x-\dfrac{2}{3}=\dfrac{3}{4}\)

\(x=\dfrac{3}{4}+\dfrac{2}{3}=\dfrac{9}{12}+\dfrac{8}{12}\)

\(x=\dfrac{17}{12}\)

\(\left(75\%.x+x\right)^2=\dfrac{1}{9}\\ =>\left(\dfrac{3}{4}x+x\right)^2=\dfrac{1}{9}\\ =>\left[{}\begin{matrix}\left(\dfrac{3}{4}x+x\right)=\dfrac{1}{3}\\\left(\dfrac{3}{4}x+x\right)=-\dfrac{1}{3}\end{matrix}\right.\\ =>\left[{}\begin{matrix}\dfrac{7}{4}x=\dfrac{1}{3}\\\dfrac{7}{4}x=-\dfrac{1}{3}\end{matrix}\right.\\ =>\left[{}\begin{matrix}x=\dfrac{4}{21}\\x=-\dfrac{4}{21}\end{matrix}\right.\)

\(\left(75\%.x+x\right)^2=\dfrac{1}{9}\)
\(\Rightarrow\left(\dfrac{3}{4}.x+1.x\right)^2=\left(\dfrac{1}{3}\right)^2\)
\(\Rightarrow\dfrac{3}{4}.x+1.x=\dfrac{1}{3}\)
\(\Rightarrow\left(\dfrac{3}{4}+1\right).x=\dfrac{1}{3}\)
\(\Rightarrow\dfrac{7}{4}.x=\dfrac{1}{3}\)
\(\Rightarrow x=\dfrac{1}{3}:\dfrac{7}{4}\)
\(\Rightarrow x=\dfrac{4}{21}\)

x= 2023

y=5

Chiều rộng tấm bìa:
\(\dfrac{3}{32}:\dfrac{3}{8}=\dfrac{1}{4}\left(m\right)\)
Chu vi tấm bìa:
\(\left(\dfrac{3}{8}+\dfrac{1}{4}\right)\times2=\dfrac{5}{4}\left(m\right)\)

Chiều rộng hình chữ nhật là :

3/32 : 3/8 = 1/4 (m)

Chu vi hình chữ nhật là :

(1/4 + 3/8) x 2 = 5/4 (m)

Đáp số : 5/4 m

\(\dfrac{2^2}{1.3}.\dfrac{3^2}{2.4}.\dfrac{4^2}{3.5}.....\dfrac{99^2}{98.100}\)
\(=\dfrac{2.2.3.3.4.4.....99.99}{1.3.2.4.3.5.....98.100}\)
\(=\dfrac{2.3.4.....99}{1.2.3.4.....98}.\dfrac{2.3.4.....99}{3.4.5.....100}\)
\(=\dfrac{99}{98}\cdot\dfrac{2}{100}\)
\(=\dfrac{99}{4900}\)

Vì \(x,y\inℤ\) nên\(\left(x+2\right)\inℤ;\left(y-1\right)\inℤ\)

Mà 5 là số nguyên tố nên tích của 5 là \(5\cdot1;1\cdot5;\left(-1\right)\cdot\left(-5\right);\left(-5\right)\cdot\left(-1\right)\)

Nếu là \(5\cdot1\) thì \(x=3;y=2\)

Nếu là \(1\cdot5\) thì \(x=-1;y=6\)

Nếu là \(\left(-1\right)\cdot\left(-5\right)\) thì \(x=-3;y=-4\)

Nếu là \(\left(-5\right)\cdot\left(-1\right)\) thì \(x=-7;y=0\)

Vậy có 4 đáp án trên thỏa mãn.

mik cần gấp bg chuẩn bị kiểm tra

\(a,MSC:170\\ \dfrac{7}{10}=\dfrac{7.17}{17.10}=\dfrac{119}{170}\\ \dfrac{-5}{15}=-\dfrac{1}{5}=\dfrac{1.34}{5.34}=\dfrac{34}{170}\\ \dfrac{3}{17}=\dfrac{3.10}{17.10}=\dfrac{30}{17}\\ b,MSC:525\\ \dfrac{-4}{-75}=\dfrac{4}{75}=\dfrac{4.7}{75.7}=\dfrac{28}{525}\\ \dfrac{-3}{5}=\dfrac{-3.105}{5.105}=\dfrac{-315}{525}\\ \dfrac{8}{35}=\dfrac{8.15}{35.15}=\dfrac{120}{525}\)

Y di vay