Factoring Polynomials
1. We are given the trinomial $$10r^3s + 35rs^4 - 100rs$$ and asked to factor it, which represents the amount paid by Ms. Umali for bananas.
2. We will find the polynomial representing the shaded area in the figure: the area of the large circle minus the combined area of the six smaller circles inside it.
### Problem 1: Factoring the Trinomial
1. Identify the greatest common factor (GCF) of all terms:
Each term contains $r$ and $s$, and the coefficients are 10, 35, and -100.
The GCF of 10, 35, and 100 is 5.
2. Factor out the GCF:
$$10r^3s + 35rs^4 - 100rs = 5rs(2r^2 + 7s^3 - 20)$$
3. The factored form is:
$$5rs(2r^2 + 7s^3 - 20)$$
This tells us the weight of bananas bought and the price per kilo relate as factors: one factor is $5rs$ representing common quantities, and the other $2r^2 + 7s^3 - 20$ could be price or weight components.
### Problem 2: Factoring the Polynomial for the Shaded Area
1. The large circle has radius $R$, so its area is:
$$A_{large} = \pi R^2$$
2. There are six small circles each with radius $r$, so combined area is:
$$A_{small} = 6 \times \pi r^2 = 6\pi r^2$$
3. The shaded area is the difference:
$$A_{shaded} = A_{large} - A_{small} = \pi R^2 - 6\pi r^2$$
4. Factor out common term $\pi$:
$$A_{shaded} = \pi (R^2 - 6r^2)$$
5. Recognize $R^2 - 6r^2$ as a difference of squares type but since 6 is not a perfect square, factoring stops here.
Final factored polynomial representing the shaded area is:
$$\pi (R^2 - 6r^2)$$