16. ADDING/SUBTRACTING
POLYNOMIALS
To add or subtract polynomials,
combine like terms.
5 2 1 2 7 4
5 2 1 2 7 4
3 5 3
x y x y
x y x y
x y
20.
2 2 2
2 2 2
2 2
2
2
a b c ab ac
a b c ab ac
a b a ab b
a b a ab b
a b a b a b
SPECIAL PRODUCTS
21.
22 2
22 2
2 2
2
2
2
5 6 2 3
ab ac a b c
ab ac a b c
a ab b a b
a ab b a b
a b a b a b
a a a a
FACTORING
30. If a = b, then:
a c b c
a c b c
a c b c
, 0
a b
c
c c
2 2
a b
, , 0a b a b
1 1
, , 0a b
a b
31. SOLVING EQUATIONS
“IN TERMS OF …”
Isolate one variable on
one side of the equation,
leaving an expression
containing the other
variable in the other side
of the equation.
10y x
37. You can solve for
two variables only
if you have two
distinct equations.
38. Two forms of the
same equation will
not be adequate.
5 15
5 15
y x
y x
39. Combine the equations in
such a way that one of
the variables cancels out,
isolate the variable, and
then plug that expression
into the other equation.
3
4
5
a b
a c
b c
40. 3
4
5
a b
a c
b c
Find the value of a + b + c.
2 2 2 12a b c
6a b c
41. SUSTITUTION
Solve for x and y: 2 13, 2x y x y
2x y 2( 2) 13
2 4 13
3 13 4
3 9
3
y y
y y
y
y
y
2 3 13
2 13 3
2 10
5
x
x
x
x
42. ELIMINATION
Solve for x and y: 2 8, 1x y x y
2 8
1
3 9
3
x y
x y
x
x
2 3 8
6 8
8 6
2
y
y
y
y
50. Solve for x: 2
11 30 0x x
2
1 2
11 11 4 1 30
2 1
11 1
2
6, 5
x
x
x x
2
1, 11, 30
4
2
a b c
b b ac
x
a
51. PROPERTIES OF THE
ROOTS
If the roots of a quadratic equations
are r1 and r2, the equation can be
written as
1 2 0x r x r
52. In a quadratic equation of the form
, the sum of the
roots is equal to –d and the
product of the roots is equal to e.
2
0x dx e
1 2
1 2
r r d
r r e
53. Solve for x: 2
11 30 0x x
2
1
2
11 30 0
5 6 0
5 0 5
6 0 6
x x
x x
x x
x x
1 2
1 2
11,
30
x x
x x
Note that:
54. To solve an exponential equation,
put both sides of the equation in the
form ax, and make a new equation
using just the exponents.
SOLVING EXPONENTIAL
EQUATIONS
55. If ax = ay, then x = y ( a ≠ 0 and a ≠ 1).
3
2 2
3
x
x
67. SOLVING INEQUALITIES
If a > b, then:
a c b c
a c b c
0,If c a c b c
0,
a b
If c
c c
1 1
, , 0a b
a b
0,If c a c b c 0,
a b
If c
c c