Assume that the rule connecting height of the candle to time is a linear one. If you do, then we have to find the equation of this line, and then use this equation to predict the height of the candle after 11 hours.
Two points on this line are (6,17.4) and (23, 7.2). The slope is thus
7.2-17.4 -6
m = --------------- = ----------- or -3/5.
23-6 10
Find the equation of the line. I'm going to use the slope-intercept formula:
y = mx + b => 7.2 = (-3/5)(23) + b. Solving for b, b = 21.
Now we know that y = (-3/5)x + 21
Let x=11 to predict the height of the candle at that time.
y = (-3/5)(11) + 21 = 14.4 inches (answer)
-43 - 4r = 3 - 27r
Add 27r to both sides. -43 - 4r + 27r = 3 -27r + 27r or -43 + 23r = 3
Add 43 to both sides. -43 + 43 +23r = 3 + 43 or 23r = 46.
Divide both sides by 23 to get r by itself. 23r / 23 = 46 / 23 or r = 2
r = 2
The answer is D) isosceles and equilateral triangle
