Step 1: Set up the partial fraction decomposition.
The denominator has a linear factor (x−3) and an irreducible quadratic factor (x2+9).
(x2+9)(x−3)x2=x−3A+x2+9Bx+C
Step 2: Multiply both sides by the common denominator (x2+9)(x−3).
x2=A(x2+9)+(Bx+C)(x−3)
Step 3: Solve for A, B, and C.
Substitute x=3:
32=A(32+9)+(B(3)+C)(3−3)
9=A(9+9)+0
9=18A
A=189=21
Expand the equation:
x2=Ax2+9A+Bx2−3Bx+Cx−3C
x2=(A+B)x2+(−3B+C)x+(9A−3C)
Equate coefficients:
Coefficient of x2:
1=A+B
Substitute A=21:
1=21+B
B=1−21=21
Coefficient of x:
0=−3B+C
Substitute B=21:
0=−3(21)+C
C=23
Constant term (for verification):
0=9A−3C
Substitute A=21 and C=23:
0=9(21)−3(23)
0=29−29
0=0
The values are consistent.
Step 4: Write the partial fraction decomposition.
(x2+9)(x−3)x2=x−321+x2+921x+23
(x2+9)(x−3)x2=2(x−3)1+2(x2+9)x+3
The final answer is 2(x−3)1+2(x2+9)x+3.
Step 1: Set up the partial fraction decomposition.
The denominator has a linear factor (x−1) and an irreducible quadratic factor (x2+4).
(x−1)(x2+4)1=x−1A+x2+4Bx+C
Step 2: Multiply both sides by the common denominator (x−1)(x2+4).
1=A(x2+4)+(Bx+C)(x−1)
Step 3: Solve for A, B, and C.
Substitute x=1:
1=A(12+4)+(B(1)+C)(1−1)
1=A(1+4)+0
1=5A
A=51
Expand the equation:
1=Ax2+4A+Bx2−Bx+Cx−C
1=(A+B)x2+(−B+C)x+(4A−C)
Equate coefficients:
Coefficient of x2:
0=A+B
Substitute A=51:
0=51+B
B=−51
Coefficient of x:
0=−B+C
Substitute B=−51:
0=−(−51)+C
0=51+C
C=−51
Constant term (for verification):
1=4A−C
Substitute A=51 and C=−51:
1=4(51)−(−51)
1=54+51
1=55
1=1
The values are consistent.
Step 4: Write the partial fraction decomposition.
(x−1)(x2+4)1=x−151+x2+4−51x−51
(x−1)(x2+4)1=5(x−1)1−5(x2+4)x+1
The final answer is 5(x−1)1−5(x2+4)x+1.
Step 1: The given equation is:
(x+3)(x+1)6x+7=x+3A+x+1B
Step 2: Multiply both sides by the common denominator (x+3)(x+1).
6x+7=A(x+1)+B(x+3)
Step 3: Solve for A and B.
To find B, substitute x=−1:
6(−1)+7=A(−1+1)+B(−1+3)
−6+7=A(0)+B(2)
1=2B
B=21
To find A, substitute x=−3:
6(−3)+7=A(−3+1)+B(−3+3)
−18+7=A(−2)+B(0)
−11=−2A
A=−2−11=211
Step 4: Evaluate (B−A).
B−A=21−211
B−A=21−11
B−A=2−10
B−A=−5
The final answer is −5.