Given that 2x + y = 7 and 3x - 2y = 3, by how much is 7x greater than 10?

  • A 1
  • B 3
  • C 7
  • D 17
waec 2016mathematics

The correct answer is C. 7

2x + y = 7...(1)

3x - 2y = 3...(2)

From (1), y = 7 - 2x for y in (2)

3x - 2(7 - 2x) = 3

3x - 14 + 4x = 3

7x + 3 + 14 = 17

x = \(\frac{17}{7}\)

Hence, 7 x \(\frac{17}{7}\)

= 17 - 10

= 7

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