Answer:
m = 3.86
Step-by-step explanation:
D = 6 / 7
D = m + 3
6 / 7 = m + 3
6 / 7 + 3 = m
m = 3.86
 
        
             
        
        
        
 Over which interval(s) is the function decreasing?
 
        
             
        
        
        
Vertical angles 2 and 5,  1 and 6, 3 and 8, 7 and 4
linear pair  1 and 5, 5 and 6, 6 and 2, 2 and 1, and also 3 and 7, 7 and 8, 8 and 4, 4 and 3
congruent angles - all vertical pairs are congruent angles
 2 congruent to 5,  1 congruent to 6, 3 congruent to 8, 7 congruent to 4 
        
             
        
        
        
<span>I note that this problem starts out with "Which is a factor of ... "  This implies that you were given several answer choices.  If that's the case, it's unfortunate that you haven't shared them.
I thought I'd try finding roots of this function using synthetic division.  See below:
f(x) = 6x^4 – 21x^3 – 4x^2 + 24x – 35
Please use " ^ " to denote exponentiation.  Thanks.
Possible zeros of this poly are factors of 35:  plus or minus 1, plus or minus 5, plus or minus 7.  Use synthetic division; determine whether or not there is a non-zero remainder in each case.  If none of these work, form rational divisors from 35 and 6 and try them:  5/6, 7/6, 1/6, etc.
Provided that you have copied down the function 
</span>f(x) = 6x^4 – 21x^3 – 4x^2 + 24x – 35  properly, this approach will eventually turn up 1 or 2 zeros of this poly.  Obviously it'd be much easier if you'd check out the possible answers given you with this problem.
By graphing this function, I found that the graph crosses the x-axis at 7/2.  There is another root.
Using synth. div. to check whether or not 7/2 is a root:
         ___________________________
7/2   /   6    -21    -4    24    -35
                   21      0   -14     35           
        ----------- ------------------------------
           6        0     -4    10       0
Because the remainder is zero, 7/2 (or 3.5) is a root of the polynomial.  Thus, (x-3.5), or (x-7/2), is a factor.
        
                    
             
        
        
        
60 = 0.20x
60/0.20 = x
300 = x <== so 60 minutes is 20% of 300 minutes