We read your photo as:

Expand (x-2y)³ using the binomial theorem.

Mathematics

ScanSolve AI Answer

This answer stops before the end.

It was cut off when it was first written. Ask ScanSolve this question again for the full working.

Step 1: Expand (x−2y)3(x-2y)^3 using the binomial theorem.
The binomial theorem states that (a+b)n=∑k=0n(nk)an−kbk(a+b)^n = \sum_{k=0}^{n} \binom{n}{k} a^{n-k} b^k.
For (x−2y)3(x-2y)^3, we have a=xa=x, b=−2yb=-2y, and n=3n=3.

(x−2y)3=(30)x3(−2y)0+(31)x2(−2y)1+(32)x1(−2y)2+(33)x0(−2y)3(x-2y)^3 = \binom{3}{0}x^3(-2y)^0 + \binom{3}{1}x^2(-2y)^1 + \binom{3}{2}x^1(-2y)^2 + \binom{3}{3}x^0(-2y)^3 =(1)x3(1)+(3)x2(−2y)+(3)x(4y2)+(1)(1)(−8y3)= (1)x^3(1) + (3)x^2(-2y) + (3)x(4y^2) + (1)(1)(-8y^3) =x3−6x2y+12xy2−8y3= x^3 - 6x^2y + 12xy^2 - 8y^3

Step 2: Multiply the expanded form by x2x^2.

x2(x−2y)3=x2(x3−6x2y+12xy2−8y3)x^2(x-2y)^3 = x^2(x^3 - 6x^2y + 12xy^2 - 8y^3) =x2⋅x3−x2⋅6x2y+x2⋅12xy2−x2⋅8y3= x^2 \cdot x^3 - x^2 \cdot 6x^2y + x^2 \cdot 12xy^2 - x^2 \cdot 8y^3 =x5−6x4y+12x3y2−8x2y3= x^5 - 6x^4y + 12x^3y^2 - 8x^2y^3

The binomial expansion is:

x5−6x4y+12x3y2−8x2y3\boxed{x^5 - 6x^4y + 12x^3y^2 - 8x^2y^3}

Step 1: Write the general term for the expansion of (x−3x)4\left(x - \frac{3}{x}\right)^4.
The general term Tr+1T_{r+1} in the expansion of (a+b)n(a+b)^n is given by Tr+1=(nr)an−rbrT_{r+1} = \binom{n}{r} a^{n-r} b^r.
Here, a=xa=x, b=−3x=−3x−1b=-\frac{3}{x} = -3x^{-1}, and n=4n=4.

Tr+1=(4r)(x)4−r(−3x−1)rT_{r+1} = \binom{4}{r} (x)^{4-r} (-3x^{-1})^r Tr+1=(4r)x4−r(−3)r(x−1)rT_{r+1} = \binom{4}{r} x^{4-r} (-3)^r (x^{-1})^r Tr+1=(4r)(−3)rx4−r−rT_{r+1} = \binom{4}{r} (-3)^r x^{4-r-r} Tr+1=(4r)(−3)rx4−2rT_{r+1} = \binom{4}{r} (-3)^r x^{4-2r}

Step 2: Find the value of rr for the term independent of xx.
For the term independent of xx, the power of xx must be 0.

4−2r=04-2r = 0 2r=42r = 4 r=2r = 2

Step 3: Substitute r=2r=2 into the general term formula.

T2+1=T3=(42)(−3)2x4−2(2)T_{2+1} = T_3 = \binom{4}{2} (-3)^2 x^{4-2(2)} T3=4!2!(4−2)!(9)x0T_3 = \frac{4!}{2!(4-2)!} (9) x^0 T3=4×3×2×1(2×1)(2×1)×9×1T_3 = \frac{4 \times 3 \times 2 \times 1}{(2 \times 1)(2 \times 1)} \times 9 \times 1 T3=244×9T_3 = \frac{24}{4} \times 9 T3=6×9T_3 = 6 \times 9 T3=54T_3 = 54

The term independent of xx is:

54\boxed{54}

Step 1: Use the binomial series expansion formula for (1+x)n(1+x)^n.
The binomial series expansion is given by (1+x)n=1+nx+n(n−1)2!x2+n(n−1)(n−2)3!x3+…(1+x)^n = 1 + nx + \frac{n(n-1)}{2!}x^2 + \frac{n(n-1)(n-2)}{3!}x^3 + \dots.
For (1−y)13(1-y)^{\frac{1}{3}}, we have x=−yx=-y and n=13n=\frac{1}{3}.

Step 2: Calculate the first term.
The first term is 1.

Step 3: Calculate the second term.

Was this helpful?

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp