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
4.) The lateral area of a figure is the area of the figure with the exception of the bases.
Given a prism with right triangle bases, the lateral area of the prism is the sum of the areas of the rectangles making up the prism.
This is given by
Lateral area = (8.94)(41) + (4)(41) + (8)(41) = 366.54 + 164 + 328 = 858.54 ≈ 859 m^2
The surface area is the sum of the bases plus the lateral area. The area of a rectangle is given by half base times height.
Surface area = 1/2 x 8 x 4 + 1/2 x 8 x 4 + 859 = 16 + 16 + 859 = 891 m^2
5.) The surface area of a cylinder is given by pi r^2h where r is the radius = 12 inches and h is the height = 17 inches.
Surface area = π x (12)^2 x 17 = 2,448π = 7,690.62 in^2 ≈ 7,691 in^2
Answer:
f(x) = x² + 8 - 16x
= x² - 16x + 8
= (x² - 16x + 64) - 64 + 8
= (x + 8)² - 56
You could sit down with several pencils and a whole pad of paper, and
divide Leda's mass by Europa's mass. But it's probably good enough
to provide an answer that's correct to 2 or 3 significant figures, and
there's a much easier way to do that:
Leda's mass . . . . approx. 1.094 x 10¹⁶
Europa's mass . . . . approx. 4.8 x 10²²
Leda's mass is about (1.094 x 10¹⁶) / (4.8 x 10²²) of Europa's mass.
(1.094 x 10¹⁶) / (4.8 x 10²²) = 2.28 x 10⁻⁷
Leda's mass is approx. <em>0.000 000 228</em> of Europa's mass.
