LESSON 3: Our main goal : The 'x' by its own
|Introduction to Elementary Algebra
Help on solving algebra math problems
Simple step by step method
Let’s say we were given this statement
As 5 divided by 5 is equal to 1 both fives disappear.
The result is that we keep the x alone, as we wanted.
Another example follows:
How can we get rid of the 3 so we keep only the x?
Well, if the number 3 is multiplying by x … we simply divide by 3 to get
Because 3 divided by 3 is equal to 1 we get x alone.
Now let’s say we were given this statement
How can we get rid of the 5 so we keep only the x?
The x is being divided by 5. In this case we multiply also by 5.
How can we get rid of the 7 so we keep only the x?
The x is being added 7 units so we make just the opposite: we subtract 7 units.
Because 7 – 7 is equal to zero both sevens disappear.
The x alone again.
This next example might seem difficult but it is actually very
Well, ‘x’ is being multiplied by 7/3. We must take the necessary action to
make the 7/3 disappear.
We ask ourselves: What is the opposite of 7/3?
Answer: Just invert the numbers. The answer is 3/7
Let’s do it
Because 3/7 multiplied by 7/3 is equal to 1 we keep only the ‘x’.
What we just made is the same as dividing 7/3 by 7/3 which could also be
done and is also equal to 1. Again we are using the opposite operation.
How can we get rid of the -2 so we keep only the x?
The x is being subtracted 2 units so we make just the opposite: we add 2 units.
Because -2 + 2 is equal to zero both 'twos' disappear.
The x is alone again.
What we did in all 4 cases was simply using the opposite operations using the same
numbers that were near the x.