Caitlin is designing a railing for a set of stairs. The railing will begin at a height of 36 inches and follow the slant of the stairs, which decreases 9 inches for every 12 horizontal inches. Which function can represent the height, y, of the railing in inches according to the horizontal distance in inches, x, from the top of the stairs? Y = –StartFraction 3 Over 4 EndFractionx + 36 y = –3x + 36 y = StartFraction 3 Over 4 EndFractionx + 36 y = 3x + 36

Given:

The railing will begin at a height of 36 inches.

Height decreases 9 inches for every 12 horizontal inches.

To find:

The function for this situation.

Solution:

Let y be the height of the railing in inches according to the horizontal distance in inches, x, from the top of the stairs.

Initial height = 36

So, y-intercept is 36.

Height decreases 9 inches for every 12 horizontal inches.  So,

Slope intercept form of a line is

Substitute and b=36.

The required function is .

Therefore, the correct option is A.

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

answer: 193

explanation:

200-7 = 193