x is the days that the first team finishes the work alone (x>8)
y --------------------------second-----------------------------------------(y>8)
In a day:
⇒ [tex]\frac{1}{x}+ \frac{1}{y} =\frac{1}{8}[/tex] (1)
If the first team works alone for two days and the second team works alone for 5 days, 5/8 of the total work still remains:
⇒ [tex]\frac{2}{x}+\frac{5}{y}=\frac{3}{8}[/tex] (2)
(1),(2) ⇒ [tex]\left \{ {{\frac{1}{x}+ \frac{1}{y} =\frac{1}{8}} \atop {\frac{2}{x}+\frac{5}{y}=\frac{3}{8}}} \right. <=>\left \{ {{x=16} \atop {y=24}} \right.[/tex]
It'll take the first team 16 days and the second team 24 days to finish the work alone
ok done. Thank to me :>