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Hey there! Today we are going to explore the magic of linear equations using a simple balance scale.
An equation is like a perfectly balanced scale. Whatever total weight is on the left side must exactly equal the total weight on the right side.
When we have an unknown value, we call it a variable and write it as a letter, like 'x'. To find out what 'x' weighs, we need to get it all by itself on one side.
To keep the scale balanced, whatever math operation you do to one side, you must do the exact same thing to the other side. If you add 3 to the left, you must add 3 to the right!
✏️ Worked example
Solve for x: x + 4 = 9
- Look at the equation: x has 4 added to it.
- To get x by itself, perform the opposite operation. The opposite of adding 4 is subtracting 4.
- Subtract 4 from both sides of the equation: x + 4 - 4 = 9 - 4.
- Simplify both sides to find your answer: x = 5.
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