A Tutorial on Solving Equations Part 2
This is a continuation of Solving Equations Part 1. As I have mentioned in that post, being able to solve equations is very important since it is used for solving more complicated problems (e.g. word problems).
In this post, we are going to solve a slightly more complicated equations. We already discussed 5 examples in the first post, so we start with our sixth example.
Example 6:
As I have mentioned in the previous examples, we need to isolate on one side of the equation and all the numbers on the other side. Here, we decide to put all
‘s on the left hand side, so we remove
on the right hand side. To do this, we subtract
from both sides of the equation.
Of course, , so, simplifying, we have
Then, we want to eliminate on the left hand side. Since it is multiplication, we therefore divide both sides of the equation by
.
Therefore, .
Example 7:
In this example, we want to avoid a negative , so it is better to put all
‘s on the right hand side of the equation. This means that we have to eliminate
from the left hand side. So, we subtract
from the left hand side, and of course, the right hand side as well.
Next, since we want to eliminate all the numbers on the right, the easiest to eliminate first is . To do this, we just add
on both sides of the equation.
.
Next, we only have one number on the right hand side which is . To eliminate it, we divide
by
. Of course, we also need to divide the other side by
.
Therefore, the answer is .
Notice also that we can add and subtract
immediately resulting to
making the process faster. You will be able to discover such strategy on your own if you solve more equations.
Example 8:
In this example, we have the form in the left hand side of the equation. To simplify this, we simply distribute the multiplication of
over
. That is
.
This is called the distributive property of multiplication over addition.
So, solving the problem above, we have
Adding to both sides of the equation, we hhave
Dividing both sides of the equation by we have
.
Example 9:
In equations with fractions, the basic strategy is to eliminate the denominator. In this example, the denominator is . Since
means
divided by
, we cancel out
by multiplying the equation by 5. Notice how 5 is distributed over the left hand side.
which is the same as
.
Simplifying, we have .
Subtracting from both sides, we have
Dividing both sides by 3, we have .
Example 10: .
We eliminate fraction by multiplying both sides of the equation by 2. That is
In the left hand side, cancels out
, so only
is left. On the right hand side, we use distributive property.
Subtracting from both sides, we have
Subtracting from both sides, we have
That’s it. In the next post, we solve more equations, particularly those that involve fractions.