x+y+z=2020 & 1/x + 1/y + 1/z=1/202 tính M =x+y/z + x+z/y + y+z/x 31/07/2021 Bởi Mackenzie x+y+z=2020 & 1/x + 1/y + 1/z=1/202 tính M =x+y/z + x+z/y + y+z/x
M+3= (1+$\frac{x+y}{z}$) +( 1+$\frac{y+z}{x}$)+ (1+$\frac{x+z}{y}$) = $\frac{x+y+z}{z}$ + $\frac{x+y+z}{x}$ +$\frac{x+y+z}{y}$ = (x +y +z) .($\frac{1}{z}$+$\frac{1}{x}$+$\frac{1}{y}$) = 2020. 1/202 = 10 Do đó: M=10-3 =7 Bình luận
M+3= (1+$\frac{x+y}{z}$) +( 1+$\frac{y+z}{x}$)+ (1+$\frac{x+z}{y}$)
= $\frac{x+y+z}{z}$ + $\frac{x+y+z}{x}$ +$\frac{x+y+z}{y}$
= (x +y +z) .($\frac{1}{z}$+$\frac{1}{x}$+$\frac{1}{y}$)
= 2020. 1/202
= 10
Do đó: M=10-3 =7