87.5k views
4 votes
Expand the expression (r – t)^4 using the binomial theorem.

User Ted Ballou
by
7.8k points

1 Answer

3 votes

Final answer:

To expand the expression (r - t)^4 using the binomial theorem, we can use the formula (a + b)^n = C(n, 0)a^nb^0 + C(n, 1)a^(n-1)b^1 + C(n, 2)a^(n-2)b^2 + ... + C(n, n-1)a^1b^(n-1) + C(n, n)a^0b^n. Plugging in the values for a, b, and n, we can simplify the expression to (r - t)^4 = r^4 + 4r^3(-t) + 6r^2(-t)^2 + 4r(-t)^3 + (-t)^4.

Step-by-step explanation:

To expand the expression (r - t)^4 using the binomial theorem, we can use the formula:

(a + b)^n = C(n, 0)a^nb^0 + C(n, 1)a^(n-1)b^1 + C(n, 2)a^(n-2)b^2 + ... + C(n, n-1)a^1b^(n-1) + C(n, n)a^0b^n

In this case, a = r and b = -t, and we're expanding to the fourth power, so n = 4. Plugging these values into the formula, we get:

(r - t)^4 = C(4, 0)r^4(-t)^0 + C(4, 1)r^3(-t)^1 + C(4, 2)r^2(-t)^2 + C(4, 3)r^1(-t)^3 + C(4, 4)r^0(-t)^4

Expanding the binomial coefficients, we have:

(r - t)^4 = r^4 + 4r^3(-t) + 6r^2(-t)^2 + 4r(-t)^3 + (-t)^4

To expand the expression (r - t)^4 using the binomial theorem, we apply the theorem which is generally written as:

(a + b)^n = a^n + n * a^(n-1) * b + n(n-1)/2! * a^(n-2) * b^2 + n(n-1)(n-2)/3! * a^(n-3) * b^3 + ...

In this case, a is r, b is -t, and n is 4. The expansion is then:

(r - t)^4 = r^4 + 4 * r^3 * (-t) + 6 * r^2 * (-t)^2 + 4 * r * (-t)^3 + (-t)^4

Which simplifies to:

r^4 - 4r^3t + 6r^2t^2 - 4rt^3 + t^4.

User Embert
by
8.7k points

No related questions found