RULES FOR ADDITION
• Put the two sets of expressions on top of each
other to add like terms
• Simplify
Ex. 1) Simplify.
(8x + 3) + (-6x + -2)
Rewrite vertically with
like terms in columns.
Solve the columns.
8x + 3
+ -6x + -2
2x + 1
Ex. 2) Simplify.
Rewrite vertically with
like terms in columns.
Solve the columns.
(-5x – 9) + (6x + 1)
-5x – 9
+ 6x + 1
= 1x – 8
RULES FOR SUBTRACTION
• The subtraction sign in front of an expression
in parentheses means that you will have to
“distribute” the negative to everything inside.
• We can rewrite the problem:
– Change the minus sign to a plus sign
– Change all of the #s inside the parentheses to their
opposites
Ex. 1) Simplify.
Rewrite as adding
the opposite.
Rewrite vertically with
like terms in columns.
Solve the columns.
(8x + 3) – (6x + 2)
(8x + 3) + (-6x + -2)
8x + 3
+ -6x + -2
2x + 1
Ex. 2) Simplify.
Rewrite as adding
the opposite.
Rewrite vertically with
like terms in columns.
Solve the columns.
(-6x + 1) – (2x – 5)
(-6x + 1) + (-2x + 5)
-6x + 1
+ -2x + 5
-8x + 6
Ex. 3)
Subtract (-2x + 5) from (-4x – 7).
Be careful with order as you
set up the subtraction problem!
Rewrite as adding
the opposite.
Rewrite vertically with
like terms in columns.
Solve the columns.
(-4x – 7) – (-2x + 5)
(-4x – 7) + (+2x + -5)
-4x + -7
+ 2x + -5
= -2x – 12
Ex. 4) Simplify.
Rewrite as adding
the opposite.
Rewrite vertically with
like terms in columns.
Solve the columns.
 7 y  1    3 y  1 
2  8
6
8
 7 y  1     3 y  1 
2  8
6 
8
7
1
y 
8
2
3
1
 y
8
6
1 1
1 y 
4 3