Answer: b) 6
Step-by-step explanation:
Given : The illuminance of a surface varies inversely with the square of its distance from the light source.
i.e. for d distance and l luminance , we have
, where k is constant. (1)
If the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters.
From (1), we have
(2)
For the distance (d) corresponds to the illuminance to 30 lumens per square meter , we have
Put value of k , we get
Then , the number of meters should the distance of the surface from the source be increased= 12 meters- 6 meters = 6 meters.
Answer:
3
Step-by-step explanation:
Answer:
1. (0,-5)
2. y= (x-1)(x+5)
3. (-5,0)
4. (1,0)
5. (-2,-9)
6. Axis of symmetry is -2.
(Not sure what is meant by equation but the symmetry point is -2.)
Im not sure if you are saying 74/5 or 7 and 4 fifths but in the case you'r saying 74/5 you would first round to see the highest number that 5 can go to without being a decimal. Which would be 70 so you would count how many times 5 can go into 70, which would be 14, so the left over is 4/5 so you would check to see if it can be simplified which it can't so the final answer is 14 and 4/5