7
algebra

Solve: 0.4(x+10)<0.2x+60.4(x + 10) < 0.2x + 6

A

x<10x < 10

B

x>10x > 10

C

x<20x < 20

D

x>20x > 20

Correct Answer: A

Choice A is the correct answer. Work with decimals or multiply to clear them.

  1. Distribute: 0.4x+4<0.2x+60.4x + 4 < 0.2x + 6
  2. Subtract 0.2x: 0.2x+4<60.2x + 4 < 6
  3. Subtract 4: 0.2x<20.2x < 2
  4. Divide by 0.2: x<10x < 10

?�� Strategic Tip:0.4×10=40.4 \times 10 = 4. Check your decimal multiplication.

Choice B is incorrect because it reverses the inequality direction. Choice C is incorrect because it might result from dividing 4 by 0.2 incorrectly. Choice D is incorrect because it combines wrong value and wrong direction.