If 2x + y = 15 , 2y + z = 25 and 2z + x = 26, what is the value of z ?


A) 4

B) 7

C) 9

D) None of these

Correct Answer:
D) None of these

Description for Correct answer:
According to question,

\( \Large y = \frac{25 - z}{2} \)

x = 26 - 2z

\( \Large \therefore 2 (26 - 2z) + \frac{25 - z}{2} = 15 \)

\( \Large 52 - 4z + \frac{25 - z}{2} = 15 \)

104 - 8z + 25 - z = 30

- 9z = 30 - 129

- 9z = - 99

\( \Large \therefore z = 11 \)

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