Answer:
Step-by-step explanation:
The given function is 
.
When we compare to 
, we have
and c=10
The equation of the axis of symmetry of a vertical parabola is:
Also from the question the axis of symmetry is x=6
We substitute the values to get:
The initial fee of $50 is essentially the y intercept because this is the value when x = 0 (x is the number of labor-hours). So b = 50.
The slope is m = 30 because each increase of 1 hour leads to the cost bumping up by 30 dollars. In other words, slope = rise/run = (change in cost)/(change in hours) = 30/1
So we plug m = 30 and b = 50 into the y = mx+b formula to get y = 30x+50
Replace y with f(x) to get f(x) = 30x+50
The linear function for the cost is f(x) = 30x+50
Note: Some books may use other letters (instead of x and f(x)), but the idea is still the same
Once you know the cost function, you replace x with 4.5 to find the amount it will cost to have a painter work for 4.5 hours.
f(x) = 30x+50
f(4.5) = 30*4.5+50
f(4.5) = 135+50
f(4.5) = 185
It will cost 185 dollars to have the painter work for 4.5 hours
Step-by-step explanation:
fill up
1. 196
2. 625
3 . 429
First find the amount of tax by multiplying 21 × 8.5%.
.085 × 21 = 1.785 = 1.79 (rounded)
Now add the tax back into the price...
21 + 1.79 = $22.79
