\(\dfrac{23,6\text{x}4,8+47,2\text{x}1,7-12,5\text{x}3,9-4,3\text{x}12,5}{15,4+14,6-13,8-7,2-6,4-5,6}\)

\(=\dfrac{23,6\text{x}4,8+23,6\text{x}3,4-12,5\left(3,9+4,3\right)}{30-21-12}\)

\(=\dfrac{23,6\text{x}\left(4,8+3,4\right)-12,5\text{x}8,2}{-3}\)

\(=\dfrac{8,2\left(23,6-12,5\right)}{-3}=-30,34\)

thank 

ĐKXĐ: x<>-1

\(\dfrac{x+1}{2}=\dfrac{8}{x+1}\)

=>\(\left(x+1\right)^2=2\cdot8=16\)

=>\(\left[{}\begin{matrix}x+1=4\\x+1=-4\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}x=3\left(nhận\right)\\x=-5\left(nhận\right)\end{matrix}\right.\)

a; \(\dfrac{x+1}{2}\) = \(\dfrac{8}{x+1}\) (\(x\ne\) -1)

    (\(x\) + 1)² = 8.2

   (\(x\) + 1)² = 16

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

     \(\left[{}\begin{matrix}x=-5\\x=3\end{matrix}\right.\)

     Vậy \(x\in\) {-5; 3}

a:

Sửa đề: MN<MP; MQ là phân giác

Xét ΔMNQ và ΔMEQ có

MN=ME

\(\widehat{NMQ}=\widehat{EMQ}\)

MQ chung

Do đó: ΔMNQ=ΔMEQ

=>NQ=EQ

b: ΔMNQ=ΔMEQ

=>\(\widehat{MNQ}=\widehat{MEQ}\)

Xét ΔMEH và ΔMNP có

\(\widehat{EMN}\) chung

ME=MN

\(\widehat{MEH}=\widehat{MNP}\)

Do đó: ΔMEH=ΔMNP

c: Xét ΔMNP có MQ là phân giác

nên \(\dfrac{NQ}{NM}=\dfrac{QP}{MP}\)

mà MN<MP

nên NQ<QP

a: Chiều rộng khu vườn sau khi mở rộng là x+3(m)

Chiều dài khu vườn sau khi mở rộng là x+10(m)

Diện tích khu vườn sau khi mở rộng là:

\(S=\left(x+3\right)\left(x+10\right)=x^2+13x+30\)(m²)

b: Khi x=20 thì \(S=20^2+13\cdot20+30=690\left(m^2\right)\)

\(M=1+2+2^2+2^3+...+2^{2022}+2^{2023}\)

\(=\left(1+2\right)+\left(2^2+2^3\right)+...+\left(2^{2022}+2^{2023}\right)\)

\(=\left(1+2\right)+2^2\left(1+2\right)+...+2^{2022}\left(1+2\right)\)

\(=3\left(1+2^2+...+2^{2022}\right)⋮3\)

In a year, there are 7 months that have 31 days

29204 : 98 = 298

-5/13 + 2/5 + -8/13 + 3/5

= (-5/13 + -8/13 ) + (2/5 + 3/5)

= - 1 + 1

= 0

0,5 . 7/13 + 0,5 . 9/13 - 0,5 . 3/13

= 0,5 . ( 7/13 + 9/13 - 3/13)

= 0,5 . 1

= 0,5

\(\dfrac{2x+1}{2}=\dfrac{8+x}{x}\)

x (2x +1) = 2 (8 +x)

2x² + x = 16 + 2x

2x² -x - 16 = 0

=> \(x=\dfrac{\sqrt{129}+1}{4}\)

\(x=\dfrac{-\sqrt{129}+1}{4}\)