LESSON 4: Ready to solve the equation
|Introduction to Elementary Algebra
Help on solving algebra math problems
Simple step by step method
We are now ready to start solving the equation below.
Solving means to know the value for 'x'.
We know the value of 'x' when we can say: 'x' is equal to …
the left side of the equal sign.
Most important rule: Because both sides of an equation are EQUAL,
any operation we do on one side must be done on the other side.
So let’s start
We already got an x of the left side. But we don’t want the x on the right side.
What can we do?
We know from the previous lesson
that we can make the +2x disappear
if we use
On the right side of the equation.
Because it is the opposite operation.
But remember: to keep things legal we must do the same thing on the
left side also.
Let’s do it
On the right side of the equal sign
Is equal to zero.
The equation becomes
On the left side we can put the 'x's together like this
It’s easy to see that
Now the equation becomes
Which is the same as
This is where we are now
If we can make the -4 disappear we finally get the x alone on the left side of the
equal sign and we can say that we solved the equation.
The opposite of -4 is +4 so let’s do it on BOTH sides.
On the left side: -4 + 4 is equal to zero.
On the right side: 7 + 4 is equal to 11.
The equation is solved !
If we use 11 in place of 'x' we will get that both sides of the equation are EQUAL.
In rapid motion...
Bye for now. More answers to algebra problems examples in a few days.
3x - 4 - 2x = 7 + 2x - 2x