Answer:
1. the y-intercept is 9.5 and it means the starting length of the candle
2. the slope is -1/2 and it means that the candle burns 1/2 an inch every hour
3. it burns an inch every 2 hours, it is 9.5 inches long, so 19 hours it'll take to burn.
Since f(x) is a polynomial with 3rd degree, then it will have 3 roots (zeroes)
One of them is real and the other two are complex conjugate roots
Since the real root is 4, then
x = 4
Since the complex root is (1 - i), then
The other root will be the conjugate of it (1 + i)
x = (1 - i)
x = (1 + i)
To find f(x) we will multiply the three factors of it
We can get the factors from the zeroes
Subtract 4 from both sides
The first factor is (x - 4)
The second factor is (x - 1 + i)
The third factor is (x - 1 - i)
We will multiply them to find f(x)
Multiply it by (x - 4)
The answer is
5x+40 factors to 5(x+8). Notice how distributing the 5 back through to each term in the parenthesis gives
5 times x = 5x
5 times 8 = 40
So 5*(x+8) = 5*x+5*8 = 5x+40
Therefore, the factors are 5 and (x+8).
The dimensions of the sandbox are 5 feet by (x+8) feet.
We don't know the numeric value of (x+8) since we don't know the value of x, so we leave it as is.
Your answers is for sure 5