10x+ 12(48-x)=520
The solution is x=28.
That is, there are 28 basketball teams, so there are 48-28 volleyball teams = 20 teams.
2. Solution: If it takes x hours to ride a bike, it takes (1-x) hours to walk.
25x+5( 1-x)=20
The solution is x=0.75.
It takes 0.75 hours to ride, so it takes 1-0.75=0.25 hours to walk.
( 1)x=2 y=7/2
(2)x=3 y=5
(3)x = 29/33y = 13/ 1 1
(4)x=6/ 13 y=22/ 13
3. Solution: Let the velocity in still water be X km/h and the velocity of water flow be Y km/h, and you will get
x+y=20
x-y= 16
X= 18 y=2。
That is, the velocity in still water is 18km/h, and the current velocity is 2km.
4. Solutions; Suppose each train is loaded with X tons of chemical fertilizer, and each carriage is loaded with Y tons of chemical fertilizer on average.
6x+ 15y=260
8x+ 10y=440
The solution is x=50 y=4.