1,7308 4.6

2,5.09 240

3,5/8

4，(b-a)*n

5,4/ 1

6,( 1)7 0.8

(2) 1 7

(3)0.4

7,0.785

8. (1) 1 ratio 15000

(2) Northwest 20 600

(3)50

9,448

Two. ×√√×

1, B2, C3, C4, A5, B.

Four, 1, 909 4.06 two and one third

495 1200 4/5

4/3 1 36

2，X=4.8 X=3.5

X=5.4 X=20/ 1 1

3,=2034 = 16.5

=3/ 1 =5/6

V. Omission ...

6. (Calculate by yourself ...)1,(1100-300)/100.

265438+900 million = 19000000

190000000*0.3* 12/ 10000000

3,(240/3*2)*240

4. Solution: Suppose you haven't read X page.

X-7/2X=75

5. Solution: There are X gold medals after+1.

X-49%X*2=4

6, 16*2*2