354 alGEbra De mystif ieD

7. x
   xx
   xx

x

(^2250)
550
50 50
55 55
5
−=
−+=
−= +=
++ −−

()()
xx=− 5

8. 9160
   440
   340340
   44 44
   3

x^2

xx

xx

x

−=

−+=

−= +=

++ −−

(3 )(3 )

===−

==−

434

4

3

4

3

x

xx

9. x

x

xx

xx

2

2

100

100 100

100 0

10 10 0

10 010

=

−−

−=

−+=

−= +=

()()

00

10 10 10 10

10 10

++ −−

xx==−

10. xx
    xx
    x

x

(^2690)
330
30
33
3
++=
++=
+=
−−
=−

()()

11. x
    xx
    x

(^20)
0
0

=

()()

12. 50
    50
    0

x^2

xx

x

=

=

=

()()