x+(x+1)+(x+2)+290+291=581
tính nhanh :
N=\(\frac{1}{337}+2\frac{1}{291}-\frac{290}{291}.\frac{1}{337}-\frac{2}{291.337}\)
\(\frac{1}{337.291}+\frac{583}{291}-\frac{2}{337.291}=\frac{583}{291}-\frac{1}{337.291}=\frac{583.337-1}{337.291}=\frac{169652}{98067}\)
tính nhanh :
N=\(\frac{1}{337}+2\frac{1}{291}-\frac{290}{291}.\frac{1}{337}-\frac{2}{291.337}\)
tính nhanh :
N=\(\frac{1}{337}+2\frac{1}{291}-\frac{290}{291}.\frac{1}{337}-\frac{2}{291.337}\)
tính nhanh :
N=\(\frac{1}{337}+2\frac{1}{291}-\frac{290}{291}.\frac{1}{337}-\frac{2}{291.337}\)
\(N=\frac{1}{337}+\frac{583}{291}-\frac{290}{291\cdot337}-\frac{2}{291\cdot337}=\frac{291-196471}{337.291}-\frac{292}{337\cdot291}=\frac{-196472}{337.291}\)
tính nhanh :
N=\(\frac{1}{337}+2\frac{1}{291}-\frac{290}{291}.\frac{1}{337}-\frac{2}{291.337}\)
Đặt\(\dfrac{1}{337}=a,\dfrac{1}{291}=b\) rồi sút gọn
\(M=\dfrac{1}{337}.2\dfrac{1}{291}-\dfrac{290}{291}.\dfrac{1}{337}-\dfrac{2}{291.337}\)
MONG MỌI NGƯỜI GIÚP VS Ạ. CẢM ƠN NHIỀU
\(M=\dfrac{1}{337}.2\dfrac{1}{291}-\dfrac{290}{291}.\dfrac{1}{337}-\dfrac{2}{291.337}\)
\(M=\dfrac{1}{337}\left(2+\dfrac{1}{291}\right)-\left(1-\dfrac{1}{291}\right).\dfrac{1}{337}-2.\dfrac{1}{291.337}\)
Thay a = 1/337 ; b = 1/291 vào M, ta được
\(M=a\left(2+b\right)-\left(1-b\right)a-2ab\)
\(M=2a+ab-a+ab-2ab\)
\(M=a\)
\(M=\dfrac{1}{337}\)
Tìm x:
(x+1)+(x+2)+...+(x+20) = 290
x+(1+2+3+...+20)=290
x+210=290
x =290-210
x = 80
x 15/2 - 1/3 x [1/4 x y]=290/3
Lớp 5 làm gì đã học 2 biến đâu ._.
ta chỉ có thể biểu diễn x qua y hoặc y qua x thôi :))
Mới lớp 5 mà học nhanh thế :v chắc tài năng trẻ ??
\(\frac{15x}{2}-\frac{1}{3}.\left(\frac{y}{4}\right)=\frac{290}{3}\)
\(< =>\frac{90x}{12}-\frac{y}{12}=\frac{1160}{12}\)
\(< =>90x-y=1160\)
\(< =>90x=1160+y\)
\(< =>x=\frac{1160+y}{90}\)
y x 15/2 - 1/3 x [1/4 x y]=290/3
\(\frac{15}{2}y-\frac{1}{3}\cdot\left(\frac{1}{4}y\right)=\frac{290}{3}\)
=> \(\frac{15y}{2}-\frac{1}{3}\cdot\frac{y}{4}=\frac{290}{3}\)
=> \(\frac{15y}{2}-\frac{y}{12}=\frac{290}{3}\)
=> \(\frac{90y}{12}-\frac{y}{12}=\frac{1160}{12}\)
=> \(90y-y=1160\)
=> \(89y=1160\)
=> \(y=\frac{1160}{89}\)