Transcript Document

Objective 24
Solve equations, combine like terms
©2002 by R. Villar
All Rights Reserved
Solve equations, combine like terms
It is usually easier to simplify an expression prior to solving an
equation...
In these examples, we will combine like terms first, and then solve
the resulting equation...
Combine the like terms –6x and –8x first...
Example
–6x – 8x = 7
Now, solve...
–14x = 7
–14
–14
x =– 1
2
You can check the original problem...
–6(–1/2) – 8(–1/2) = 7
3
+ 4
=7√
Example:
–4x + 23 + 6x + 23 = – 2
Combine the like terms first…–4x with +6x
and +23 with +23
2x + 46 = – 2
– 46
–46
2x
= –48
2
2
x = – 24
Check
–4(–24) + 23 + 6(–24) + 23 = –2
96 + 23 – 144 + 23 = – 2
√
Let’s look at an example that has variables on both sides of the
equation...
Example:
5x + 6 = 2x – 3
The strategy to solve this type of problem is to get variables on
one side, and numbers (constants) on the other side.
variable side
5x + 6
–6
5x
–2x
3x
x
number side
= 2x – 3
–6
= 2x – 9
–2x
=
–9
= –3