Math Problem Statement

In the expansion of X the power of seven parentheses X0 4/2+ K over X to the power of three parentheses to the power of seven the constant term is 168 find the value of K

Solution

Let's break down the given expression step by step.

We are asked to find the value of KK in the expansion of:

(x7(x042+Kx3))7\left( x^7 \left( \frac{x^0 4}{2} + \frac{K}{x^3} \right) \right)^7

Let's clarify the expression first. The original expression seems unclear with the notation provided. Based on interpretation, I assume the correct expression is:

(x7(42+Kx3))7\left( x^7 \left( \frac{4}{2} + \frac{K}{x^3} \right) \right)^7

Simplifying the inner terms:

(x7(2+Kx3))7\left( x^7 \left( 2 + \frac{K}{x^3} \right) \right)^7

Now, we distribute the x7x^7 inside the parentheses:

(x72+x7Kx3)7=(2x7+Kx4)7\left( x^7 \cdot 2 + x^7 \cdot \frac{K}{x^3} \right)^7 = \left( 2x^7 + Kx^4 \right)^7

We now expand (2x7+Kx4)7\left( 2x^7 + Kx^4 \right)^7 using the binomial theorem:

(2x7+Kx4)7=r=07(7r)(2x7)7r(Kx4)r(2x^7 + Kx^4)^7 = \sum_{r=0}^{7} \binom{7}{r} (2x^7)^{7-r} (Kx^4)^r

We want the constant term in the expansion. To find that, we look for the term where the powers of xx cancel out, i.e., where the exponent of xx is zero.

General term in the expansion:

(7r)(2x7)7r(Kx4)r=(7r)27rx7(7r)Krx4r\binom{7}{r} (2x^7)^{7-r} (Kx^4)^r = \binom{7}{r} 2^{7-r} x^{7(7-r)} K^r x^{4r} =(7r)27rKrx493r= \binom{7}{r} 2^{7-r} K^r x^{49 - 3r}

For the constant term, the exponent of xx must be zero: 493r=049 - 3r = 0 Solving for rr: r=493=7r = \frac{49}{3} = 7

So, we need the term with r=7r = 7.

Substituting r=7r = 7 into the general term: (77)277K7x493(7)=(77)K7x0\binom{7}{7} 2^{7-7} K^7 x^{49 - 3(7)} = \binom{7}{7} K^7 x^0

Thus, the constant term is K7K^7.

We are given that the constant term is 168, so: K7=168K^7 = 168

Taking the seventh root of both sides: K=1687K = \sqrt[7]{168}

Let me calculate the exact value of KK.The value of KK is approximately 2.082.08.

Would you like more details or further clarification? Here are five questions to

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Binomial Expansion
Exponent Laws
Constant Term

Formulas

Binomial Theorem: (a + b)^n = Σ (nCr) * a^(n-r) * b^r
Exponent Rule: x^a * x^b = x^(a+b)

Theorems

Binomial Theorem

Suitable Grade Level

Grades 10-12