Algebra Factorization And Geometry
1. **Factorize the expression (a):**
Given: $4a^2 + 12ab$
Step 1: Identify common factors.
Step 2: Both terms have a common factor of $4a$.
Step 3: Factor out $4a$:
$$4a^2 + 12ab = 4a(a + 3b)$$
2. **Factorize the expression (b):**
Given: $3pr + 6qr - 2pt - 4qt$
Step 1: Group terms: $(3pr + 6qr) - (2pt + 4qt)$
Step 2: Factor each group:
$$3r(p + 2q) - 2t(p + 2q)$$
Step 3: Factor out the common binomial:
$$ (p + 2q)(3r - 2t) $$
3. **Inverse proportionality problem:**
Given $y$ is inversely proportional to the cube root of $x$,
so $y = \frac{k}{\sqrt[3]{x}}$ for some constant $k$.
Step 1: Use the given values $y = 3.5$ when $x = 27$:
$$3.5 = \frac{k}{\sqrt[3]{27}} = \frac{k}{3}$$
Step 2: Solve for $k$:
$$k = 3.5 \times 3 = 10.5$$
Step 3: Find $y$ when $x = 125$:
$$y = \frac{10.5}{\sqrt[3]{125}} = \frac{10.5}{5} = 2.1$$
4. **Find the midpoint of $AB$:**
Given points:
$$A(3, -3), \, B(-8, 10)$$
Step 1: Midpoint formula is:
$$M = \left( \frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2} \right)$$
Step 2: Calculate:
$$x_m = \frac{3 + (-8)}{2} = \frac{-5}{2} = -2.5$$
$$y_m = \frac{-3 + 10}{2} = \frac{7}{2} = 3.5$$
Step 3: Midpoint is:
$$M(-2.5, 3.5)$$
5. **Calculate smallest possible height of the triangle:**
Given:
- Area $= 15$ m$^2$ (correct to nearest $1$ m$^2$)
- Base $= 6.6$ m (correct to nearest $0.1$ m)
Step 1: Since area is rounded to the nearest m$^2$, smallest possible area before rounding up is:
$$15 - 0.5 = 14.5\text{ m}^2$$
Step 2: Since base is rounded to nearest 0.1 m, smallest possible base before rounding up is:
$$6.6 - 0.05 = 6.55\text{ m}$$
Step 3: Area formula for triangle:
$$A = \frac{1}{2} \times base \times height$$
Step 4: Solve for height:
$$height = \frac{2A}{base} = \frac{2 \times 14.5}{6.55} \approx 4.427$$
Step 5: The smallest possible height is approximately $4.427$ m.