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Add up all 5 equations given below. What do you notice?

Solve the system and find the values of *a*, *b*,
*c* , *d* and *e*.

*b* + *c* + *d* + *e* = 4

*a* + *c* + *d* + *e* = 5

*a* + *b* + *d* + *e* = 1

*a* + *b* + *c* + *e* = 2

*a* + *b* + *c* + *d* = 0