Math Problem Statement
Expand and simplify the binomial: (3a - 2b)^5
Solution
To expand and simplify the binomial (3a−2b)5, we use the Binomial Theorem, which states:
(x+y)n=∑k=0n(kn)xn−kyk
Here:
- n=5 (the power),
- x=3a and y=−2b.
The general term is given as:
Tk=(k5)(3a)5−k(−2b)k
Now we calculate each term by substituting values of k from 0 to 5:
Step-by-step Expansion:
-
For k=0:
T0=(05)(3a)5(−2b)0=1⋅243a5⋅1=243a5
-
For k=1:
T1=(15)(3a)4(−2b)1=5⋅81a4⋅(−2b)=−810a4b
-
For k=2:
T2=(25)(3a)3(−2b)2=10⋅27a3⋅4b2=1080a3b2
-
For k=3:
T3=(35)(3a)2(−2b)3=10⋅9a2⋅(−8b3)=−720a2b3
-
For k=4:
T4=(45)(3a)1(−2b)4=5⋅3a⋅16b4=240ab4
-
For k=5:
T5=(55)(3a)0(−2b)5=1⋅1⋅(−32b5)=−32b5
Combine All Terms:
Adding all terms together, we get:
(3a−2b)5=243a5−810a4b+1080a3b2−720a2b3+240ab4−32b5
Final Answer:
243a5−810a4b+1080a3b2−720a2b3+240ab4−32b5
Let me know if you need further clarification or steps explained!
Related Questions:
- How does the binomial theorem work for negative terms?
- Can you expand (x+y)6 step-by-step?
- How do you find the general term of a binomial expansion?
- What is Pascal’s Triangle and how is it related to binomial coefficients?
- How can the binomial theorem be applied to approximations?
Tip:
The binomial theorem is a quick way to expand powers of binomials without direct multiplication.