I think the answer is 7 hours. Not sure 100% sure
Yes it does match the graph
i believe your answers would be
1/2c+7 and 2H-9
When we sort the terms in descending order, we get 3x^6 - 4x^3 + 8x + 9
The exponents decrease (from 6 to 3 to 1 to 0) with the largest exponent term on the left side and the smallest on the right side.
Fill in the missing terms to get 3x^6 + 0x^5 + 0x^4 + (-4x^3) + 0x^2 + 8x^1 + 9x^0
So the sequence of coefficients are 3, 0, 0, -4, 0, 8, 9
Given

To determine whether the function represents exponential growth or exponential decay, and the y-intercept.
now,
It is given that,

The exponential functions are of the form,

If a is positive and b is greater than 1, then it represents exponential growth.
And, if a is positive and b is greater than 0 and less than 1, then it represents exponential decay.
Since b=1/3<1.
Then, the given function represents exponential decay.
The y- intercept of the function is,

Hence, the y-intercept is 0.99.