Correct Answer: Option A

Explanation

\(314_{10} - 256_7 = 340_x\)
Convert 2567 and 340x to base 10, such that:
314 - 139 = 3x\(^2\) + 4x
=> \(3x^2\) + 4x - 175 = 0 (quadratic)
Factorising, (x - 7) (3x + 25) = 0,
either x = 7 or x = -25/3 ( but x cannot be negative)

Therefore, x = 7.

There is an explanation video available below.

• Rhesus factor miscarriage? Answer this

  4 Answers   ·   Biology   ·   1 day ago
• Copper reacts with oxygen to form two oxides X and Y on analysis, 1.535g of X yielded 1.365g if copper... Answer this

  2 Answers   ·   6 years ago
• In electrovalency, the valence electrons are transferred and the atomic number is (a) Also stabilized (b) stabilized (c) unaffected (d)... Answer this

  3 Answers   ·   Chemistry   ·   19 hours ago