8
algebra

Solve for xx: 7x12>97x - 12 > 9

A

x>3x > 3

B

x<3x < 3

C

x>37x > -\frac{3}{7}

D

x>21x > 21

Correct Answer: A

Choice A is the correct answer. This standard two-step inequality follows a predictable solving pattern.

  1. Add 12: 7x12+12>9+127x - 12 + 12 > 9 + 12, giving 7x>217x > 21
  2. Divide by 7: 7x7>217\frac{7x}{7} > \frac{21}{7}, giving x>3x > 3
  3. Verify: Try x=4x = 4: 7(4)12=2812=16>97(4) - 12 = 28 - 12 = 16 > 9 ??n ?�� Strategic Tip: Keep operations organized: deal with constants first, then coefficients.

Choice B is incorrect because it reverses the inequality without mathematical reason. Choice C is incorrect because it appears to confusingly divide 9 by -12 or similar, leading to an incorrect fraction. Choice D is incorrect because it represents the intermediate step 7x>217x > 21 without completing the division.