How do you solve -9 < 4x + 3 < 11?

1 Answer
Aug 29, 2015

3<x<2

Explanation:

Given
XXXX9<4x+3<11

Things you can do with expressions in an inequality which maintain the inequality:

  • Add the same amount to each expression
  • Subtract the same amount from each expression
  • Divide each expression by the same amount provided the amount is greater than zero
  • Multiply each expression by the same amount provided the amount is greater than zero

So, we can subtract 3 from each expression, to get:
XXXX12<4x<8

Then we can divide each expression by 4, to get:
XXXX3<x<2