\(13,7.\left(-2,56\right)+46,31\div0,5-\left[86,3.2,56+53,69\div\left(-0,5\right)\right]\)

\(=\)\(-35,072+92,62-\left[220,928-107,38\right]\)

\(=\)\(57,548-220,928+107,38\)

\(=\)\(-163,38+107,38\)

\(=\)\(-56\)

=-56 nha bạn

HT

3x2+2y2=7xy3x2+2y2=7xy

⇔3x2−7xy+2y2=0⇔3x2−7xy+2y2=0

⇔3x2−6xy−xy+2y2=0⇔3x2−6xy−xy+2y2=0

⇔3x(x−2y)−y(x−2y)=0⇔3x(x−2y)−y(x−2y)=0

⇔(3x−y)(x−2y)=0⇔(3x−y)(x−2y)=0

⇔[3x−y=0x−2y=0⇔[3x−y=0x−2y=0 ⇔[3x=yx=2y⇔[3x=yx=2y

+) TH1 : y=3xy=3x

⇔A=3x+y7y−x+6x−9y2x+y⇔A=3x+y7y−x+6x−9y2x+y

=3x+3x7.3x−x+6x−9.3x2x+3x=3x+3x7.3x−x+6x−9.3x2x+3x

=9x20x+−21x5x=9x20x+−21x5x

=−154=−154

+) TH2 : x=2yx=2y

⇔A=3x+y7y−x+6x−9y2x+y⇔A=3x+y7y−x+6x−9y2x+y

=3.2y+y7y−2y+6.2y−9y2.2y+y=3.2y+y7y−2y+6.2y−9y2.2y+y

=7y5y+3y5y=7y5y+3y5y

=2=2

Vậy...

 4.5 ,31.16

4.5; 3116

MÀ CÁI HÌNH THỨ 2 BÊN GÓC PHẢI LÀ CỦA BÀI 3 NHA

     2¹¹.\(\frac{9^2}{3^5}\).16²

=2^{11.\(\frac{\left(3^2\right)^2}{3^5}\)}.(2⁴)²

=2¹¹.\(\frac{3^4}{3^5}\).2⁸

=2¹⁹.\(\frac{1}{3}\)

=\(\frac{2^{19}}{3}\)

2/8 + 2/3 = 11/12 nha

đáp số : x = 2,4

giải thích các bước giải

\(\frac{x^2}{6}\)\(=\frac{24}{25}\)

Áp dụng tính chất hai phân số bằng nhau thì tích chéo của chúng bằng nhau

ta có : \(x^2\)\(.25=6.24\)

\(x^2\)\(.25=144\)

\(x^2\)\(=144:25=\frac{144}{25}\)\(=5,76\)

\(x^2\)\(=5,76=2,4^2\)

\(--->x=2,4\)

\(\frac{x^2}{6}=\frac{24}{25}\)

\(\Rightarrow x^2=\frac{24}{25}.6=\frac{144}{25}\)

\(\Rightarrow\orbr{\begin{cases}x^2=12^2\\x^2=\left(-12\right)^2\end{cases}}\Rightarrow\orbr{\begin{cases}x=12\\x=-12\end{cases}}\)

ủa bn cũng trl linh tinh mà?!

\(\frac{50%}{0,7}=\frac{-2}{2x+1}\)

\(\Rightarrow\frac{5}{7}=\frac{-2}{2x+1}\)

=> 5 . ( 2x + 1 ) = -2 . 7

=> 10x + 1 = -14

=> 10x = -15

=> x = -1,5

Vậy x = -1,5

đáp số \(:\frac{217}{50}\)

giải thích các bước giải

\(\left(3\frac{1}{2}-x\right)\)\(.1\frac{1}{4}\)\(=-1\frac{1}{20}\)\(=-\frac{21}{20}\)

\(\left(\frac{7}{2}-x\right)\)\(\frac{.5}{4}\)\(=-\frac{21}{20}\)

\(\frac{7}{2}\)\(-x=-\frac{21}{20}\)\(:\frac{5}{4}\)\(=-\frac{21}{20}\)\(.\frac{4}{5}\)\(=-\frac{21}{25}\)

\(x=\frac{7}{2}\)\(--\frac{21}{25}\)\(=\frac{7}{2}\)\(+\frac{21}{25}\)\(=\frac{175}{50}\)\(+\frac{42}{50}\)\(=\frac{217}{50}\)

{31/2-x] . 11/4 = -11/20

31/2-x=-11/20:11/4

31/2-x=-1/5

x=31/2-[-1/5]

x=157/10