(1) perimeter = (length+width) *2=30, so length+width =30/2= 15.

Look at the hint: length and width =5. Just add up the two equations.

Length+width+length-width = 15+5 Two lengths =20, then 1 length = 10 width =5.

⑵ Suppose Kobayashi bought X stamps for 50 cents, then bought 40-X stamps in 1 garden, and then used the latter condition to get an equation with a total value of 22.5: 0.5X+ 1*(40-X)=22.5.

0.5X+40-X=22.5

40-0.5X=22.5

40-22.5 = 0.5 times

X= 17.5*2=35

So Kobayashi bought 35 fifty cents, 5 1 yuan.

(3) Assuming there are X buses, CMB will have 5-X buses.

24X+ 18(5-X)= 1 14 24X+90- 18X = 1 14

6X= 1 14-90=24 X=4

Answer bus 4 CMB 1

(4) If there are X rabbits, then the chicken is 20+X (note here that the chicken has two legs and the rabbit has four legs). Equation:

4X+2(20+X)=280 4X+40+2X=280

6X=240 X=40

The answer is 40 rabbits and 60 chickens.

If the rabbit has X, then the chicken has X+20.

4X-2(X+20)=40 2X=80 X=40

The answer is 40 rabbits and 60 chickens.