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When you have finished this page, try the Equations 4 Quiz.
RECAP: In the previous pages, you learned that addition and subtraction of positive and negative numbers within equations with mystery doors can be done. On this page equations with multiplication and mystery doors will be looked at.
In this equation multiplication involving positive numbers is examined. Three times a number equals fifteen. To find the number three should be multiplied by, one must divide each side of the equation by three. Three divided by three is one and one times the number behind the mystery door is that number. Three into fifteen will equal the number behind the mystery door.
3 *
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15
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5 |
By inserting the number into the equation three times five equals fifteen.
What about negative numbers in equations? Let's look at the following example. Negative three times the number behind the mystery door equals negative fifteen. By dividing the negative three by negative three, one gets the number one which will be multiplied by the number behind the mystery door. The number negative fifteen divided by negative three is five. The number behind the mystery door is five.
-3 *
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-15
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5 |
If we look at the original equation and insert the number five in, it all checks out.
