a) \(x+546=46\\ x=46-546\\ x=-500\)

b) \(2x-19\times3=27\\ 2x-57=27\\ 2x=27+57\\ 2x=84\\ x=84:2\\ x=42\)

c) \(x+12=23+3\times3^4\\ x+12=23+3\times81\\ x=23+243-12\\ x=254\)

d) \(x-12=3-3\times2^4\\ x-12=3-3\times16\\ x=3-48+12\\ x=-33\)

e) \(\left(27-x\right)\left(x+9\right)=0\\ \Rightarrow\left[{}\begin{matrix}27-x=0\\x+9=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=27\\x=-9\end{matrix}\right.\)

f) \(\left(-x\right)\left(x-43\right)=0\\ \Rightarrow\left[{}\begin{matrix}-x=0\\x-43=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=0\\x=43\end{matrix}\right.\)

a) x + 546 = 46

x = 46 - 546

x = -500

b) 2x - 19 x 3 = 27

2x - 57 = 27

2x = 27 + 57

2x = 84

x = 84 : 2

x = 42

c) x + 12 = 23 + 3 x 3⁴

x + 12 = 23 + 3 x 81

x + 12 = 23 + 243

x + 12 = 266

x = 266 - 12

x = 254

d) x - 12 = 3 - 3 x 2⁴

x - 12 = 3 - 3 x 16

x - 12 = 3 - 48

x - 12 = -45

x = -45 + 12

x = -33

e) (27 - x) x (x + 9) = 0

TH1: 27 - x = 0

x = 27 - 0

x = 27

TH2: x + 9 = 0

x = 0 + 9

x = 9

⇒ x = 27 hoặc x = 9

f) (-x) x (x - 43) = 0

TH1: -x = 0

⇒ x = 0

TH2: x - 43 = 0

x = 0 + 43

x = 43

⇒ x = 0 hoặc x = 43.

\(a,\dfrac{3}{5}+\dfrac{-5}{9}=\dfrac{27-25}{45}=\dfrac{2}{49}.\)

\(c,\dfrac{-27}{23}+\dfrac{5}{21}+\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}=\dfrac{-23}{23}+\dfrac{21}{21}+\dfrac{1}{2}=-1+1+\dfrac{1}{2}=\dfrac{1}{2}.\)

\(d,\dfrac{-8}{9}+\dfrac{1}{9}.\dfrac{2}{9}+\dfrac{1}{9}.\dfrac{7}{9}=\dfrac{-8}{9}+\dfrac{1}{9}.\left(\dfrac{2}{9}+\dfrac{7}{9}\right)=\dfrac{-8}{9}+\dfrac{1}{9}.1=\dfrac{-8+1}{9}=\dfrac{-7}{9}.\)

a, x= 3

b, ko có x thỏa mãn

c, x= 3

d, x= 2

a: x=3

b: \(2x-1=2\)

hay \(x=\dfrac{3}{2}\)

c: \(\Leftrightarrow\left[{}\begin{matrix}2x-3=3\\2x-3=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=0\end{matrix}\right.\)

Tách từng câu ra giùm, như này ai giải nổi:)))))

a)\(\left(\dfrac{1}{9}:\dfrac{8}{27}\right):\left(\dfrac{16}{48}:\dfrac{8}{21}\right)\)

=\(\dfrac{3}{8}:\dfrac{7}{8}\)

=\(\dfrac{3}{7}\)

b)\(\dfrac{19}{23}+\dfrac{1}{9}\cdot\dfrac{36}{23}\)

=\(\dfrac{19}{23}+\left(\dfrac{1}{9}\cdot\dfrac{36}{23}\right)\)

=\(\dfrac{19}{23}+\left(\dfrac{1}{1}\cdot\dfrac{4}{23}\right)\)

=\(\dfrac{19}{23}+\dfrac{4}{23}\)

=\(\dfrac{23}{23}=1\)

c)\(\left(\dfrac{13}{23}+\dfrac{1313}{2323}-\dfrac{131313}{232323}\right)\cdot\left(\dfrac{1}{3}+\dfrac{1}{4}-\dfrac{7}{12}\right)\)

=\(\left(\dfrac{13}{23}+\dfrac{1313}{2323}-\dfrac{131313}{232323}\right)\cdot\left(\dfrac{4}{12}+\dfrac{3}{12}-\dfrac{7}{12}\right)\)

=\(\left(\dfrac{13}{23}+\dfrac{1313}{2323}-\dfrac{131313}{232323}\right)\cdot0\)

=0

chúc bn học tốt!

Mai tui giải cho hem

Ta có:

\(A=\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{13.15}\)

\(A=\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{13}-\frac{1}{15}\)

\(A=\frac{1}{3}-\frac{1}{15}=\frac{4}{15}\)

\(B=2.\left(\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{9.10}\right)\)

\(B=2.\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{9}-\frac{1}{10}\right)\)

\(B=2.\left(\frac{1}{1}-\frac{1}{10}\right)=2.\frac{9}{10}\)

\(B=\frac{9}{5}\)

Ok chị. Nhớ là sáng tầm 10h nhé ! Mà chỉ cần giải phần B thui phần A em biết làm rồi .

Bài 1 :

Theo thứ tự tăng dần : -|-2015| ; -11 ; -10 ; -|-9| ; 0 ; 10 ; 12 ; 23.

Bài 2 :

a) 1125 - ( 374 + 1125 ) + ( - 65 + 374 )

= 1125 - 374 - 1125 + ( -65 ) + 374

= ( 1125 - 1125 ) + [ ( -374 ) + 374 ] + ( -65 )

= 0 + 0 + ( -65 )

= -65

b) -23 . 63 + 23 . 21 - 58

= ( -23 + 23 ) . ( 63 + 21 - 58 )

= 0 . 26

= 0

c) -2003 + ( -21 + 75 + 2003 )

= (-2003 ) + ( -21 ) + 75 + 2003

= [ ( -2003 ) + 2003 ] + [ ( -21 ) + 75 ]

= 0 + 54

= 54

d) 942 - 2567 + 2563 - 1942

= ( 942 - 1942 ) - ( 2567 - 2563 )

= (-1000 ) - 4

= - 1004

e) 12 - 12 + 11 + 10 - 9 + 8 - 7 + 5 - 4 + 3 + 2 - 1

= ( 12 - 12 ) + 11 + ( 10 - 9 ) + ( 8 - 7 ) + ( 5 - 4 ) + 3 + ( 2 - 1 )

= 0 + 11 + 1 + 1 + 1 + 3 + 1

= 18

kinh,khiếp

1. Tính:

a) 23 + 24 - ( 65 x 2 - 4 ) x 4 + 66 + 44 - ( 54 : 9 x 9 : 9 + 45 ) : 1 + 1 - 1 x ( 23 + 23 - 23 x 2 +1 ) = 51

b) 4444444444444444444444444444444444444444444444444444444444444444444 : 1

= 4444444444444444444444444444444444444444444444444444444444444444444

c) 3⁰ = 0

d) 1/1 = 1

e)

a) - 530

b) 44444444444444444444444444444444444444444444444444444444444444444444

c) 0

d) 1

e) Em là em

-530

444444444444444444444444444444444444444444444444444444444444444

0

1

...