Tìm y :
a/ 67845 – y = 29361
Tìm y : a) 67845 – y = 29361
a) 67845 – y = 29361
y = 67845 – 29361
y = 38484
a) 67845 – y = 29361 b) y : 208 = 317
a) 67845 – y = 29361
y = 678445 - 29361
y = 649034
b) y : 208 = 317
y = 317 x 208
y = 65936
a) 67845 – y = 29361
y = 678445 - 29361
y = 649034
b) y : 208 = 317
y = 317 x 208
y = 65936
a) 67 845 - y = 29 361
y = 67 845 - 29 361
y = 649 034
b) y : 208 = 317
y = 317 x 208
y = 65 936
67845 x 123 =
bài 1:
b,67845:312
( x + 1259 ) x 5 = 67845
( x + 1259 ) x 5 = 67845
( x + 1259 ) = 67845 : 5
( x + 1259 ) = 13569
x = 13569 - 1259
x = 12310
Mình nghĩ đề bài sai bạn ạ
tk nhé
ai k mình mình k lại
(x+1259)x5=12345+45691
(x+1259)x5=58036
x+1259 =58036:5
x+1259 =11607,2
x=11607,2-1259
x=10348,2
bài 1: tính
a,3-3/4 =
d,67845:312=
các bạn phải làm tính nha đừng có viết luôn nha
tìm x,y thuộc Z ,biêt: (2x-1).(2x+1)=-35
tìm c,y thuộc Z , biết: (x+1)^2 + (y+1)^2 + (x-y)^2 =2
tìm x,y thuộc Z, biết: (x^2-8).(x^2-15)<0
tìm x,y thuộc Z biết: x=6.y và|x|-|y|=60
tìm a,b thuộc Z biết: |a|+|b|<2
a,5/y=1/2 (tìm y)
b,42/25:y/5=6/5(tìm y)
Giup tui vs
a) \(\dfrac{5}{y}=\dfrac{1}{2}\)
\(y=\dfrac{5\times2}{1}=10\)
b) \(\dfrac{42}{25}:\dfrac{y}{5}=\dfrac{6}{5}\)
\(\dfrac{y}{5}=\dfrac{42}{25}:\dfrac{6}{5}\)
\(\dfrac{y}{5}=\dfrac{7}{5}\)
\(y=7\)
\(\dfrac{5}{y}=\dfrac{1}{2}\\ =>y=5.2:1=10\)
\(\dfrac{42}{25}:\dfrac{y}{5}=\dfrac{6}{5}\\ =>\dfrac{y}{5}=\dfrac{42}{25}:\dfrac{6}{5}=\dfrac{42}{25}.\dfrac{5}{6}=\dfrac{7}{5}\\ =>y=\dfrac{7}{5}.5=7\)
a) \(\dfrac{5}{y}=\dfrac{1}{2}\)
\(\Rightarrow y=5\cdot2:1=10\)
b) \(\dfrac{42}{25}:\dfrac{y}{5}=\dfrac{6}{5}\)
\(\dfrac{y}{5}=\dfrac{42}{25}:\dfrac{6}{5}=\dfrac{7}{5}\)
\(\dfrac{y}{5}=\dfrac{7}{5}\)
\(\Rightarrow y=7\)
Bài 4: tìm 3 số a,b,c biết : a/5=b/7=c/10 và 2a+3b-4c=-81
Bài 5 : tìm y
a,y/4=9/y
b, y+7/20=5/y+7
c, 4-5y/3=y+2/5
Nhanhhh tickkkkkk
Bài 5 :
a) \(\dfrac{y}{4}=\dfrac{9}{y}\)
\(\Rightarrow y^2=36\left(y\ne0\right)\)
\(\Rightarrow y=\pm6\)
b) \(\dfrac{y+7}{20}=\dfrac{5}{y+7}\left(y\ne-7\right)\)
\(\Rightarrow\left(y+7\right)^2=100=10^2\)
\(\Rightarrow\left[{}\begin{matrix}y+7=10\\y+7=-10\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}y=3\\y=-17\end{matrix}\right.\)
c) \(\dfrac{4-5y}{3}=\dfrac{y+2}{5}\)
\(\Rightarrow5\left(4-5y\right)=3\left(y+2\right)\)
\(\Rightarrow20-25y=3y+6\)
\(\Rightarrow28y=14\)
\(\Rightarrow y=\dfrac{14}{28}=\dfrac{1}{2}\)
Bài 4 :
\(\dfrac{a}{5}=\dfrac{b}{7}=\dfrac{c}{10}\)
\(\Rightarrow\dfrac{2a}{10}=\dfrac{3b}{21}=\dfrac{4c}{40}=\dfrac{2a+3b-4c}{10+21-40}=\dfrac{81}{-9}=-9\)
\(\Rightarrow\left\{{}\begin{matrix}a=-9.5=-45\\b=-9.7=-63\\c=-9.10=-90\end{matrix}\right.\)
Đính chính Bài 4 :
\(...\dfrac{2a+3b-4c}{10+21-40}=\dfrac{-81}{-9}=9\)
\(\Rightarrow\left\{{}\begin{matrix}a=9.4=36\\b=9.7=63\\c=9.10=90\end{matrix}\right.\)