Speed = Distance/Time. Let speed be V, distance D and time T
a)Given: D₁ =45km, V₁=x km/h
V₁=D₁/T
V₁=45/T OR T= 45/V₁
b) Given : D₂ =48 km and V₂ = V₁ + 4 km/h
V₂ = 48/T, but V₂ = V₁+4, then:
V₁+4 = 48/T OR T=48/(V₁+4). Since Time is same, then we can write:
45/V₁ =48/(V₁+4), solve for V₁:
45V₁ + 180 = 48V₁
3V₁ =180 and V₁ = x = 60 km/h
The first option is correct. For the following question, the simplified expression for the volume is 8x3 + 14x2 + 3x.
![\bf \textit{zeros at } \begin{cases} x = -3\implies &x+3=0\\ x = -1\implies &x+1=0\\ x = 4\implies &x-4=0 \end{cases}\qquad \implies (x+3)(x+1)(x-4)=\stackrel{y}{0} \\\\\\ (x^2+4x+3)(x-4)=0\implies x^3~~\begin{matrix}+ 4x^2 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~+3x~~\begin{matrix} -4x^2 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~-16x-12=0 \\\\\\ x^3-13x-12=0](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bzeros%20at%20%7D%20%5Cbegin%7Bcases%7D%20x%20%3D%20-3%5Cimplies%20%26x%2B3%3D0%5C%5C%20x%20%3D%20-1%5Cimplies%20%26x%2B1%3D0%5C%5C%20x%20%3D%204%5Cimplies%20%26x-4%3D0%20%5Cend%7Bcases%7D%5Cqquad%20%5Cimplies%20%28x%2B3%29%28x%2B1%29%28x-4%29%3D%5Cstackrel%7By%7D%7B0%7D%20%5C%5C%5C%5C%5C%5C%20%28x%5E2%2B4x%2B3%29%28x-4%29%3D0%5Cimplies%20x%5E3~~%5Cbegin%7Bmatrix%7D%2B%204x%5E2%20%5C%5C%5B-0.7em%5D%5Ccline%7B1-1%7D%5C%5C%5B-5pt%5D%5Cend%7Bmatrix%7D~~%2B3x~~%5Cbegin%7Bmatrix%7D%20-4x%5E2%20%5C%5C%5B-0.7em%5D%5Ccline%7B1-1%7D%5C%5C%5B-5pt%5D%5Cend%7Bmatrix%7D~~-16x-12%3D0%20%5C%5C%5C%5C%5C%5C%20x%5E3-13x-12%3D0)
we know that f(-2) = 24, namely when x = -2, y = 24, let's see if that's true

darn!! no dice.... hmmmm wait a second.... 4 * 6 = 24, if we could just use a common factor of 4 on the function, that common factor times 6 will give us 24, let's check.
![\bf 4(x^3-13x-12)=y\implies \stackrel{x = -2}{4[~~(-2)^3-13(-2)-12~~]}=y \\\\\\ 4[~~-8+26-22~~]=y\implies 4[6]=y\implies 24=y \\\\[-0.35em] ~\dotfill\\\\ ~\hfill 4x^3-52x-48=y~\hfill](https://tex.z-dn.net/?f=%5Cbf%204%28x%5E3-13x-12%29%3Dy%5Cimplies%20%5Cstackrel%7Bx%20%3D%20-2%7D%7B4%5B~~%28-2%29%5E3-13%28-2%29-12~~%5D%7D%3Dy%20%5C%5C%5C%5C%5C%5C%204%5B~~-8%2B26-22~~%5D%3Dy%5Cimplies%204%5B6%5D%3Dy%5Cimplies%2024%3Dy%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20~%5Chfill%204x%5E3-52x-48%3Dy~%5Chfill)
Yes, it is a scientific notation, please mark brainliest
Answer:
Step-by-step explanation:

Similar triangles

Pythagorean theorem
