tim y:1,1\(\times\)1,2\(\times\)1,3\(\times\)y=y\(\times\)2,1\(\times\)2,2\(\times\)2,3
a)6,5+1,2+3,5-5,2+6,5-4,8
b) (-4,3×1,1+1,1×4,5):(-0,5:0,05+ 10,01)
c) (6,7+5,66-3,7+4,34)×(-76,6×1,2+7,66×12)
a) \(6,5+1,2+3,5-5,2+6,5-4,8\)
\(=6,5+1,2+3,5+6,5-5,2-4,8\)
\(=\left(6,5+3,5+6,5\right)+1,2-\left(5,2+4,8\right)\)
\(=16,5+1,2-10\)
\(=17,7-10\)
\(=7,7.\)
b) \(\left(-4,3.1,1+1,1.4,5\right):\left(-0,5:0,05+10,01\right)\)
\(=\left\{1,1.\left[\left(-4,3\right)+4,5\right]\right\}:\left[\left(-10\right)+10,01\right]\)
\(=\left(1,1.0,2\right):0,01\)
\(=0,22:0,01\)
\(=22.\)
c) \(\left(6,7+5,66-3,7+4,34\right).\left(-76,6.1,2+7,66.12\right)\)
\(=\left[\left(5,66+4,34\right)+\left(6,7-3,7\right)\right].\left[7,66.\left(-10\right).1,2+7,66.12\right]\)
\(=\left[10+3\right].\left[7,66.\left(-12\right)+7,66.12\right]\)
\(=13.\left\{7,66.\left[\left(-12\right)+12\right]\right\}\)
\(=13.0\)
\(=0.\)
Chúc bạn học tốt!
Tim y:
a) 3\(\times\)y=850\(-\)2\(\times\)y
b) 3\(\times\)y\(\times\)(y+2)=2\(\times\)(y+100)
a) 3y + 2y = 850
5y = 850
y = 850 : 5
y = 170
Ps: Ko nên tự trả lời ,tự !
a) 3 * y = 850 - 2 * y
3y + 2y = 850
5y = 850
y = 850 : 5 = 170
Hãy cho biết chất nào dẫn điện kém nhất , vì sao
Vật liệu Bạc là 1,6×10^-6,Đồng 1,7×10-6,Vonfram 5,5×10-6,Nhôm 2,8×10-6,constantan 0,5×10-4,Nicrom 1,1×10-4
Tìm y :
\(1,2\times\left(\dfrac{2,4\times y-0,23}{y}-0,05\right)=1,44\)
Ta có: \(1,2\left(\dfrac{2,4y-0,23}{y}-0,05\right)=1,44\)
\(\Rightarrow\dfrac{2,4y-0,23}{y}-0,05=1,2\)
\(\Rightarrow\dfrac{2,4y-0,23}{y}=1,25\)
\(\Rightarrow2,4y-0,23=1,25y\)
\(\Rightarrow2,4y-1,25y=0,23\)
\(\Rightarrow1,15y=0,23\)
\(\Rightarrow y=0,2=\dfrac{1}{5}\)
Vậy \(y=\dfrac{1}{5}.\)
\(1,2.\left(\dfrac{2,4y-0,23}{y}-0,05\right)=1,44\)
\(\Rightarrow\dfrac{2,4y-0,23}{y}-0,05=1,2\)
\(\Rightarrow\dfrac{2,4y-0,23}{y}=1,25\)
\(\Rightarrow2,4y-0,23=1,25y\)
\(\Rightarrow2,4y-1,25y=0,23\)
\(\Rightarrow1,15y=0,23\)
\(\Rightarrow y=\dfrac{0,23}{1,15}=0,2\)
Vậy y = 0,2
Tìm y :
\(1,2\times\left(\frac{2,4\times y-0,23}{y}-0,05\right)=1,44\)
\(\frac{2,4\cdot y-0,23}{y}=1,44\div1,2\)
\(\frac{2,4\cdot y-0,23}{y}=1,2\)
\(x\times y^2\times z^3+x^2\times y^3\times z^4+...+x^{2017}\times y^{2018}\times z^{2019}\)
cho 2 đa thức \(A=2\times x^2\times y^3-3\times x^3\times y^2+x^2\times y^2+1\)
\(B=2\times x^2\times y^3-3\times x^3\times y^2-x^2\times y^2+2\)
Tính \(2\times A-\left(B-\left(A-\left(-4\times B\right)\right)\right)\)
\(\left(^{x^2}\times y\right)^{^5}\times\left(x^2\times y^2\right)^7\times\left(x\times y^2\right)^6\times x^3\)
\(\left(x^2.y\right)^5.\left(x^2.y^2\right)^7.\left(x.y^2\right)^6.x^3\)
\(=x^{10}.y^5.x^{14}.y^{14}.x^6.y^{12}.x^3\)
\(=x^{33}.y^{31}\)
tim x \(x\times y+2\times x-y=5\)5
xy + 2x - y = 5
=> x(y + 2) - y - 2 = 3
=> x(y + 2) - (y + 2) = 3
=> (x - 1)(y + 2) = 3
x-1 | 1 | -1 | 3 | -3 |
y+2 | 3 | -3 | 1 | -1 |
x | 2 | 0 | 4 | -2 |
y | 1 | -5 | -1 | -3 |
\(xy+2x-y=5\)
\(\Leftrightarrow x\left(y+2\right)-\left(y+2\right)=3\)
\(\Leftrightarrow\left(y+2\right)\left(x-1\right)=3\)
\(\Leftrightarrow y+2;x-1\inƯ\left(3\right)=\left\{-3;-1;1;3\right\}\)
Ta có bảng
x-1 | -3 | -1 | 1 | 3 |
x | -2 | 0 | 2 | 4 |
y+2 | -1 | -3 | 3 | 1 |
y | -3 | -5 | 1 | -1 |