Question 1136639
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a + b + c + d + e = 21    (1)

a + b = 6                 (2)

b + c = 10                (3)

c + d = 7                 (4)

d + e = 9                 (5)



1.  From equations (2) and (5), substitute  a + b = 6  and   d + e = 9  into equation (1). You will get

    6 + c + 9 = 21,  which implies  c = 21 - 6 - 9 = 6.



2.  Now equation   (3) becomes  b + 6 = 10,  giving  b = 10 - 6 = 4,

    while equation (4) becomes  6 + d =  7,  giving  d =  7 - 6 = 1.



3.  Now equation   (2) becomes  a + 4 = 6,  giving  a = 6 - 4 = 2,

    while equation (5) becomes  1 + e = 9,  giving  e = 9 - 1 = 8.



<U>Answer</U>.  a= 2,  b= 4,  c= 6,  d= 1  and  e= 8.
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Solved.