6x+5=14
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Opens the whiteboard: the tutor draws and talks through this lesson, and you can ask questions.
Transcript
We need to find the mystery number x that makes this equation true. Think of an equation like a balanced scale: whatever we do to one side, we must do to the other.
- 6x + 5 = 14
Our goal is to get x alone on one side. The 5 is being added to 6x, so we subtract 5 from both sides.
- Step 1: Remove the 5
6x + 5 - 5 = 14 - 5On the left, plus 5 and minus 5 cancel out.
6x = 9Now 6 is multiplied by x, so we divide both sides by 6. Divide both sides by 6.
- Step 2: Remove the 6
\frac{6x}{6} = \frac{9}{6}The 6s cancel on the left, and 9 divided by 6 simplifies to 3 halves.
x = \frac{3}{2} \text{ or } 1.5Let's check: 6 times 1.5 is 9, plus 5 is 14. Perfect! Quick quiz: solve 3x minus 2 equals 10. What is x? To solve any linear equation, isolate x by undoing addition or subtraction first, then multiplication or division.
- Check: 6(1.5) + 5 = 9 + 5 = 14 ✓
- Undo: subtract/add, then divide/multiply
Quick quiz
Q1. Solve: 3x - 2 = 10
Add 2 to both sides: 3x = 12. Divide by 3: x = 4.
