x/2= 19.6 x=39.2

39.2/0.02= 1960

(2) Set oil weight xkg and barrel weight ykg.

X+y=9

X/2+y=5.5 gives x=7 y=2.

So the barrel weighs 2 kilograms.

(3) 1 hectare = 1 ten thousand square meters

The circumference of a square is 1200m, each side is 300m long and the area is 90000m2.

90,000 m2 =9 hectares 250 * 9 = 2,250.

(4) 20 yellow flowers and 10 yellow flowers

(5) One * * * seven and a half hours between10: 45 and 20: 15.

85 * 7.5 = 637.5 km.

(6)(4.3*2.6-5. 18)/ 12=0.5

(7) If the base is x, the area is 4x.

4x= 120 x=30 30* Height * 1/2= 120 Height =8.

Let this number be X.

4x-5*0.8=6.4 x=0.6

(9) Set the height x

(4.6+6.4)* x * 1/2 = 12. 1x = 2.2

10: 37.5

1 1: 80

12: 0.3388t1.392m.

13: 62.5

14: 1)7.5 2)6

15: 100