Tìm y:
Y÷4×Y+0,25=2,45
Y×2+Y×0,5=6,25
99,75÷(Y×6)=4,75
tìm y:
a, y-2 và 2/3=1 và 2/3:2 và 1/3
b,4,75-y:0,5=2,98
tìm y:y + 23 = 6 x y +17
y + 23 = 6 x y + 17
=> 5 x y = 6
=> y = 6/5
Tìm y
y : 0,25 + y : 0,5 + y : 0,5 + y + y : 0,01 = 214
\(y:0,25+y:0,5+y:0,5+y+y:0,01=214\\ \Rightarrow y\times4+y\times2+y\times2+y\times1+y\times100=214\\ \Rightarrow y\times\left(4+2+2+1+100\right)=214\\ \Rightarrow y\times109=214\\ \Rightarrow y=\dfrac{214}{109}\)
tìm y
y : 0,25 + y :0,5 +y+y: 0,01 = 214
17 , 75 -( 0,5 * y :2-4,2 ) = 15
Tìm 2 số x, y biết :
( x – 0,5)^2+( y + 0,25)^2 = 0
Ta có:
\(\left(x-0,5\right)^2+\left(y+0,25\right)^2=0\)
\(\Leftrightarrow x-0,5=y+0,25=0\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=0,5\\y=-0,25\end{matrix}\right.\)
Tìm y: y+y:0,5+y:0,25+y:0,125=15
\(y+y:0,5+y:0,25+y:0,125=15\)
\(y.1+y.2+y.4+y.8=15\)
\(y.\left(1+2+4+8\right)=15\)
\(y.15=15\)
\(y=1\)
. là dấu nhân!
Tìm x,y (x-0,5)^2+(y+0,25)^2=0
\(\left(x-0,5\right)^2+\left(y+0,25\right)^2=0\)
Do \(\hept{\begin{cases}\left(x-0,5\right)^2\ge0\\\left(y+0,25\right)^2\ge0\end{cases}\Rightarrow VT\ge0}\)
Dấu "=" xảy ra \(\Leftrightarrow\hept{\begin{cases}x-0,5=0\\y+0,25=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=0,5\\y=-0,25\end{cases}}}\)
Vậy \(\hept{\begin{cases}x=0,5\\y=-0,25\end{cases}}\)
vì \(\hept{\begin{cases}\left(x-0,5\right)^2\ge0\\\left(y+0,25\right)\ge0\end{cases}}\)
mà \(\left(x-0,25\right)^2+\left(y-0,25\right)^2=0\)
\(\Rightarrow\hept{\begin{cases}\left(x+0,5\right)^2=0\\\left(y-0,25\right)^2=0\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}x+0,5=0\\y-0,25=0\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}x=-0,5\\y=0,25\end{cases}}\)
1. Tìm y :
Y x 7:5 + 4x 8 = 134
2. Tính nhanh
\(\dfrac{1}{4}\): 0,25 - \(\dfrac{1}{8}\) : 0,125 + \(\dfrac{1}{2}\) : 0,5 -\(\dfrac{1}{10}\)
1)\(y\times7:5+4\times8=134\)
\(\Leftrightarrow y\times7:5+32=134\)
\(\Leftrightarrow y\times7:5=102\)
\(\Leftrightarrow y\times7=510\)
\(\Leftrightarrow y=72,86\)
2) \(\dfrac{1}{4}:0,25-\dfrac{1}{8}:0,125+\dfrac{1}{2}:0,5-\dfrac{1}{10}\)
\(=0,25:0,25-0,125:0,125+0,5:0,5-\dfrac{1}{10}\)
\(=1-1+1-\dfrac{1}{10}\)
\(=\dfrac{9}{10}\)
2/ Tìm y:
y + \(\dfrac{1}{3}\) x 4 = 12 \(\dfrac{2}{5}\) + y = \(\dfrac{12}{35}\) x \(\dfrac{14}{9}\)
\(y=12-\left(\dfrac{1}{3}\times4\right)=12-\dfrac{4}{3}=\dfrac{32}{3}\)
\(y=\left(\dfrac{12}{35}\times\dfrac{14}{9}\right)-\dfrac{2}{5}=\dfrac{8}{15}-\dfrac{2}{5}=\dfrac{2}{15}\)
a) \(y+\dfrac{1}{3}\times4=12\)
\(y+\dfrac{1}{3}=12:4\)
\(y+\dfrac{1}{3}=3\)
\(y=3-\dfrac{1}{3}\)
\(y=\dfrac{8}{3}\)
b) \(\dfrac{2}{5}+y=\dfrac{12}{35}\times\dfrac{14}{9}\)
\(\dfrac{2}{5}+y=\dfrac{8}{15}\)
\(y=\dfrac{8}{15}-\dfrac{2}{5}\)
\(y=\dfrac{2}{15}\)