x:13=41
( - x ) + ( -52 ) + ( -41 ) - ( - 41 ) - (- 12) = - 13
\(\left(-x\right)+\left(-52\right)+\left(-41\right)-\left(-41\right)-\left(-12\right)=-13\\ \Rightarrow\left(-x\right)-52-41+41+12=-13\\ \Rightarrow\left(-x\right)+\left(12-52\right)+\left(41-41\right)=-13\\ \Rightarrow\left(-x\right)+\left(-40\right)=-13\\ \Rightarrow-x=\left(-13\right)-\left(-40\right)\\ \Rightarrow-x=27\\ \Rightarrow x=-27\)
Đăng ko ai trl thì thôi chứ đừng đăng nhiều bị xóa đó
Lời giải:
$(-x)+(-52)+(-41)-(-41)-(-12)=-13$
$(-x)+(-52)-(-12)=-13$
$(-x)-52+12=-13$
$(-x)-(52-12)=-13$
$(-x)-40=-13$
$-x=40+(-13)=40-13=27$
$x=-27$
Mọi người ơi help me !\
Bài 1:
a) 11 x 62 + (- 12 ) x 11 + 50 +11
b) 5/ 13 + -5 / 7 + -20 /41 + 8/ 13 + -21 / 41
11×[(62+(-12)]+50+11
11×51+50+11
561+50+11
611+11
622
(5/13+8/13)+(-20/41+-21/41)+-5/7
1+-1+-5/7
-5/7
a)
11 x 62 + -12 x 11 + 50 + 11
= 11 x (62 + -12) + 50 + 11
= 11 x 50 + 50 + 11
= (11 + 11) x (50 + 50)
= 22 x 100
= 2200
b)
5/13 + -5/7 + -20/41 + 8/13 + -21/41
= (5/13 + 8/13) + (-20/41 + -21/41) + -5/7
= 1 + -1 + -5/7
= -5/7
thực hiện phép tính :
a, -1/2 + 19/23+ -9/2+ 4/23 +3 /-6
b. 5/13+ -5/7 +-20/41 + 8/13 +-21/41
c.-5/7 x 19/41 + 5/7 x -21/41 + 5/7
d. 7/3 +1/2 - -3/70
Đây là phân số
tìm x thuộc z: 27/23+-4/23+1/2+-4/8<x<7/3+13/41+28/41
\(\frac{27}{23}+\frac{-4}{23}+\frac{1}{2}+\frac{-4}{8}< x< \frac{7}{3}+\frac{13}{41}+\frac{28}{41}\)
\(\Rightarrow\frac{27}{23}-\frac{4}{23}+\frac{1}{2}-\frac{4}{8}< x< \frac{7}{3}+\frac{13}{41}+\frac{28}{41}\)
\(\Rightarrow1+0< x< \frac{7}{3}+\frac{3}{3}\)
\(\Rightarrow1< x< \frac{10}{3}\)
\(\Rightarrow1< x< 3,333333333\)
\(\Rightarrow x\in\left\{2;3\right\}\)
Vậy : ....
ta co : \(\frac{27}{23}+\frac{-4}{23}+\frac{1}{2}+\frac{-4}{8}< x< \frac{7}{3}+\frac{13}{41}+\frac{28}{41}\)
=> \(1< x< \frac{10}{3}\)
vi x la so nguyen => \(1< x\le3\)
con lai ban tu lam
Tìm số tự nhiên x, biết: x : 13 = 41
x-4/5*9-4/9*13-4/13*17-.....-4/41*45=37/45
=>x-(1/5-1/9+1/9-1/13+...+1/41-1/45)=37/45
=>x-8/45=37/45
=>x=1
Tinh bang cach thuan tien :
41 / 27 x 13 / 18 - 13 / 18 x 14 / 27
41 / 27 x 13 / 18 - 13 / 18 x 14 / 27 = ( 41 / 27 - 14 / 27 ) x 13 / 18 = 27 / 27 x 13 / 18 = 1 x 13 / 18 = 13 / 18
Tìm x:
a. 1337 + 13 x x = 6745 b. 142 x x – 41 x x – x = 408000
\(a,1337+13\times x=6745\\ \Rightarrow13\times x=6745-1337\\ \Rightarrow x=5408:13\\ \Rightarrow x=416\\ b,142\times x-41\times x-x=408000\\ \Rightarrow x\times\left(142-41-1\right)=408000\\ \Rightarrow x\times100=408000\\ \Rightarrow x=408000:100\\ \Rightarrow x=4080\)
a. 1337 + 13 x x = 6745
13 x x = 6745-1337
13 x x = 5408
x = 5408 : 13
x = 416
b. 142 x x – 41 x x – x = 408000
142 x x – 41 x x – x x 1 = 408000
(142-41-1) x x = 408 000
100 x x = 408000
x = 408 000:100
x = 4080
Tính S = 1/5 x 9 + 1/9 x 13 + 1/13 x 17+ ........+ 1/41 x 45
\(4.S=\frac{4}{5.9}+\frac{4}{9.13}+...+\frac{4}{41.45}\)
\(4S=\frac{1}{5}-\frac{1}{6}+\frac{1}{9}-\frac{1}{13}+...+\frac{1}{41}-\frac{1}{45}\)
\(4S=\frac{1}{5}-\frac{1}{45}=\frac{8}{45}\)
\(S=\frac{8}{45}:4=\frac{2}{45}\)
\(S=\frac{1}{5.9}+\frac{1}{9.13}+\frac{1}{13.17}+...+\frac{1}{41.45}\)
\(\Rightarrow4S=\frac{4}{5.9}+\frac{4}{9.13}+\frac{4}{13.17}+...+\frac{4}{41.45}\)
\(\Rightarrow4S=\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{13}+\frac{1}{13}-\frac{1}{17}+...+\frac{1}{41}-\frac{1}{45}\)
\(\Rightarrow4S=\frac{1}{5}-\frac{1}{45}=\frac{8}{45}\Rightarrow S=\frac{8}{45}:4=\frac{2}{45}\)
~ Hok tốt ~