Show:
x3
x4
x5
x6
x7
100

3x3

9

100

4x3=

12

100

5x5=

25
100

6x4

24

100

7x3=

21

200
3x6=

18

200

4x5=

20

200

5x7=

35
200

6x6

36

200

7x4

28

300
3x8=
24
300

4x7=

28

300

5x9

45
300

6x8

48

300

7x7

49

400

3x11

33

400

4x8=

32

400

5x10

50

400

6x9=

54

400

7x8

56

500

3x9=

27

500

4x9=

36

500

5x11=

55

500

6x11

66

500

7x9

63