Question

_+_=8 _+_=6 ___ 13 8

Answer 1

4+4=8 3+3=6 130+8 = 138

Answer 2

We write the given problem as follows :

a + b = 8

+ +

c - d = 6

ll ll

13 8

Thus we form four equations :

• a + b = 8 ..... (1)
• a + c = 13 ..... (2)
• b + d = 8 ..... (3)
• c - d = 6 ..... (4)

Adding (3) and (4), we have

b + d + c - d = 8 + 6

or, b + c = 14 ..... (5)

Subtracting (2) from (1), we get

a + b - a - c = 8 - 13

or, b - c = - 5 ..... (6)

Now we add (5) and (6):

b + c + b - c = 14 - 5

or, 2b = 9

or, b = 4.5

Putting b = 4.5 in (5), we get

4.5 + c = 14

or, c = 14 - 4.5

or, c = 9.5

Putting c = 9.5 in (2), we get

a + 9.5 = 13

or, a = 13 - 9.5

or, a = 3.5

Putting b = 4.5 in (3), we get

4.5 + d = 8

or, d = 8 - 4.5

or, d = 3.5

Therefore we have the following structure :

(3.5) + (4.5) = 8

+ +

(9.5) - (3.5) = 6

ll ll

13 8