Solve 3x + 1 < 7
Linear inequality, worked out line by line the way a teacher would write it.
Answer
| Solution | x < 2 |
| Interval notation | (−∞, 2) |
Step-by-step solution
4 steps-
1 Given3 x + 1 < 7
Solve for x.
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2 Subtract 1 from both sides
Like an equation, an inequality stays true when the same amount is added to or subtracted from both sides. Only multiplying or dividing by a negative number needs extra care: it reverses the sign.
3 x < 6Move the constant terms to the right.
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3 Divide both sides by 3x < 2
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4 Solutionx < 2\qquad \left( -\infty, 2 \right)
Check with test values
| x | Left side | Right side | Holds? |
|---|---|---|---|
| 1 | 4 | 7 | ✓ true |
| 3 | 10 | 7 | ✗ false |
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