Sign Up
School Account Sign Up
Contributor: Stefani Allegretti. Lesson ID: 14179
Do you like math puzzles? Get ready to find the missing pieces of math equations with an unknown using multiplicative inverse!
Solving equations can be fun!
They are like puzzles that always fit together; you just have to find the right pieces and connect them!
Fortunately, there are many different strategies for solving math puzzles, especially the ones with missing pieces or unknown answers.
One of those strategies is the multiplicative inverse.
Get ready to dive in and learn how to solve for x using the multiplicative inverse!
Equation: 3x = 12
First, think about what the missing piece is.
It is the x.
Hmmm.
You can use an awesome math tool called the multiplicative inverse property to find this missing puzzle piece!
Before solving this problem, watch this video to learn more about the multiplicative inverse property.
The multiplicative inverse is the number you would multiply a number or fraction by to make it equal 1.
Time to try to solve this equation using this handy math tool!
In this equation, 3x = 12, you can multiply each side of the equation by the inverse of 3, which is 1/3. Multiply 3x by 1/3. This cancels out the 3s and leaves you with x.
Next, multiply 12 by 1/3, which leaves you with 12/3. 12 divided by 3 equals 4!
And there it is!
The solution is x = 4.
To verify your solution, substitute x = 4 (or 4) back into the original equation 3x = 12.
It sure is!
Watch this video to see this in action!
Time to practice another equation!
Equation: 2x - 4 = 8
In this example, you first need to simplify the equation by eliminating the -4.
So, to simplify the equation, you can perform the inverse operation of subtraction, which is addition, on both sides of the equation.
So, you will add 4 to the left side of the equation, which cancels out the -4.
Then, add 4 to the right side of the equation.
8 + 4 = 12
Now, you have a simplified equation.
Equation: 2x = 12
You can multiply both sides of the equation by the inverse of 2 (or 2/1), which is ½.
| 2 | x | 1 | = | 2 | = | 1 |
| 1 | 2 | 2 |
This leaves you with x on the left side.
Now, the equation looks like this.
| x | = | 12 | x | 1 |
| 1 | 2 |
Another way to look at this is x = 12/2.
12 divided by 2 = 6
So, x = 6!
Nice work, math wiz!
Now, it's time to check your work!
Substitute the x =6 back into the equation to check it!
2x - 4 = 8
2(6) - 4 = 8
12 - 4 = 8!
It is correct!
Awesome work!
Solving these puzzles isn't so hard after all!
Now, head to the Got It? section for some fun practice!
Supplies
FAVORITE
Like