Answer:
x = 9/4
Step-by-step explanation:
Locate point G on segment DE so that DG = 1 and GE = 4. CG is parallel to AD, so ΔCGE ~ ΔABC. Corresponding sides are proportional.
AB/BC = CG/GE
x/1 = 9/4
x = 9/4
_____
<em>Additional comment</em>
Using the given triangles, you can write the proportion statement as ...
(9+x)/x = 5/1
We judge this to take more steps to solve, so we prefer the method shown above.
2000(3/5)
6000/5
1200
So 1200 doctors used brand X
Answer:
6 friends
Step-by-step explanation:
Take 1/7 multiply by 5/6
Answer:
- train: 40 kph
- plane: 140 kph
Step-by-step explanation:
Let t represent the speed of the train in km/h. Then 4t-20 is the speed of the plane. Travel times are the same, so we can use the formula ...
time = distance/speed
and equate the travel times.
110/t = 385/(4t-20)
Cross multiplying gives ...
110(4t -20) = 385t
440t -2200 = 385t . . . . . eliminate parentheses
55t -2200 = 0 . . . . . . . . . subtract 385t
t -40 = 0 . . . . . . . . . divide by 55
t = 40 . . . . . . . . . . . add 40; train's speed is 40 kph
4t -20 = 140 . . . . . . find plane's speed; 140 kph
The train's speed is 40 km/h; the plane's speed is 140 km/h.
_____
<em>Check</em>
Train's travel time = 110 km/(40 km/h) = 2.75 h.
Plane's travel time = 385 km/(140 km/h) = 2.75 h.
That would be choice C the limit of f(x) is 2.
