Here are the solutions to the problems.
Question 5:
Simplify (2−y41−y−41y45).
Step 1: Simplify the denominator of the fraction.
y41−y−41=y41−y411
Find a common denominator:
=y41(y41)2−1=y41y21−1
Step 2: Substitute the simplified denominator back into the fraction and simplify.
y41−y−41y45=y41y21−1y45
Multiply by the reciprocal of the denominator:
=y45×y21−1y41
Combine the terms in the numerator using exponent rules (am×an=am+n):
=y21−1y45+41=y21−1y46=y21−1y23
Step 3: Substitute this simplified fraction back into the original expression and combine terms.
2−y21−1y23
Find a common denominator, which is y21−1:
=y21−12(y21−1)−y21−1y23
=y21−12y21−2−y23
Rearrange the terms in the numerator:
=y21−1−y23+2y21−2
This can also be written by multiplying the numerator and denominator by −1:
=1−y21y23−2y21+2
The simplified expression is 1−y21y23−2y21+2.
Question 6:
Split (x−1)(x+2)1 into partial fractions.
Step 1: Set up the partial fraction decomposition.
For distinct linear factors, the form is:
(x−1)(x+2)1=x−1A+x+2B
Step 2: Multiply both sides by the common denominator (x−1)(x+2).
1=A(x+2)+B(x−1)
Step 3: Solve for A and B.
To find A, let x=1:
1=A(1+2)+B(1−1)
1=3A
A=31
To find B, let x=−2:
1=A(−2+2)+B(−2−1)
1=−3B
B=−31
Step 4: Substitute the values of A and B back into the partial fraction form.
(x−1)(x+2)1=x−131+x+2−31
=3(x−1)1−3(x+2)1
The partial fraction decomposition is 3(x−1)1−3(x+2)1.
Question 7:
Split (x−2)2(x+1)3 into partial fractions.
Step 1: Set up the partial fraction decomposition.
For a repeated linear factor (x−2)2 and a distinct linear factor (x+1), the form is:
(x−2)2(x+1)3=x−2A+(x−2)2B+x+1C
Step 2: Multiply both sides by the common denominator (x−2)2(x+1).
3=A(x−2)(x+1)+B(x+1)+C(x−2)2
Step 3: Solve for A, B, and C.
To find B, let x=2:
3=A(2−2)(2+1)+B(2+1)+C(2−2)2
3=0+B(3)+0
3=3B
B=1
To find C, let x=−1:
3=A(−1−2)(−1+1)+B(−1+1)+C(−1−2)2
3=0+0+C(−3)2
3=9C
C=93=31
To find A, substitute B=1, C=31 and choose a convenient value for x, for example x=0: