9.5 Addition, Subtraction, and Complex Fractions Do Now: Obj: to add and subtract rational...
10
9.5 Addition, Subtraction, and Complex Fractions 5 1 5 3 ) 1 5 4 2 1 3 2 ) 2 6 3 6 4 6 1 Do Now: Obj: to add and subtract rational expressions Remember : you need a common denominator!
-
Upload
tobias-stephens -
Category
Documents
-
view
214 -
download
0
Transcript of 9.5 Addition, Subtraction, and Complex Fractions Do Now: Obj: to add and subtract rational...
9.5 Addition, Subtraction, and Complex Fractions
5
1
5
3 )1
5
4 2
1
3
2 )2
6
3
6
4
6
1
Do Now:
Obj: to add and subtract rational expressions
Remember: you need a common denominator!
Ex 1:
xxa
2
7
2
3 )
x2
4
x
2
4
6
4
3 )
xx
xb
4
63
x
x4
)2(3
x
xor
Ex 2:
233 363
4)
xx
x
xa
Needs a common denominator 1st
Sometimes it helps to factor the denominators to find your LCD.
)12(33
423
xx
x
x LCD: 3x3(2x+1)
)12(3
)(
)12(3
)12(433
xx
xx
xx
x
)12(3
483
2
xx
xx)12(3
483
2
xx
xx
9
1
96
1)
22
xxx
xb
)3)(3(
1
)3)(3(
1
xxxx
x
)3)(3)(3(
)3(1
)3)(3)(3(
)3)(1(
xxx
x
xxx
xx
LCD: (x+3)(x+3)(x-3)
)3)(3)(3(
3332
xxx
xxxx
)3)(3)(3(
632
xxx
xx
HW:
43
21
.c3
4
2
1
6
4
3
2
Do Now:
Complex Fraction – a fraction with a fraction in the numerator and/or
denominator.
Such as:
How would you simplify this complex fraction?
Multiply the top by the reciprocal of the bottom!
52
31
6
5
2
5
3
1
Steps to make complex fractions easier.
1. Condense the numerator and denominator into one fraction each. (if necessary)
2. Multiply the numerator by the denominator.
3. Simplify the remaining fraction.
Ex 1:Ex 1:
13
41
43
xx
x
)1)(4()4(3
)1)(4()1(
)4(3
xxx
xxx
x
)1)(4(1231
)4(3
xxxx
x
)1)(4(114
)4(3
xxxx
114
)1)(4(
)4(
3
x
xx
x
)114)(4(
)1)(4(3
xx
xx
114
33or
114
)1(3
x
x
x
x
Ex 2:
xx
x1
14
12
)1()1(
)1(4
12
xxx
xxxx
)1(14
12
xxxx
x
)1(151
2
xxxx
15
)1(
1
2
x
xx
x )15)(1(
)1(2
xx
xx
15
2
x
x
Ex 3:
31
31
32
94
2
xx
xx
)3(1
)3(1
)3(2
)3)(3(4
xx
xxx
)3)(3()3(
)3)(3()3(
)3)(3()3(2
)3)(3(4
xxx
xxx
xxx
xx
)3)(3()3()3(
)3)(3()3(24
xxxxxxx
)3)(3(2
)3)(3(102
xxxxx
x
x
xx
xx
x
2
)3)(3(
)3)(3(
102
xxx
xxx
2)3)(3(
)3)(3)(102(
x
x
2
102
x
x
2
)5(2
x
x 5
