2x - 15
15 is decreased that is the key word here which indicates subtraction.
twice a number with given variable x is 2x
subtraction always goes behind so 2x - 15
I think the answer to the expression would be D. (10 - 2) x 4 because (10 - 2) would be multiplied 4 times, which means it would be four times greater. I hope this made sense and also helped you in some way.
Answer:
0.675 m/s
Step-by-step explanation:
Let height of shadow= y,CD=x
Height of man=2 m
Speed of man= 

Therefore, 


Differentiate w.r.t t



When the man is 4 m from the building
Then, we have x=12-4=8 m

Substitute the values in above equation then, we get


Substitute the values then we get

Hence, the length of his shadow on the building decreasing at the rate 0.675 m/s.
I will create a set of arbitrary constants (x1,y1) (x2,y2)
slope = y2-y1/x2-x1
y = (y2-y1/x2-x1)x + b
y2 = (y2-y1/x2-x1)x2 + b
b = y2 - (y2-y1/x2-x1)x2
y = (y2-y1/x2-x1)x + [y2 - (y2-y1/x2-x1)]
Choose any points and just
Plug the values and you have a linear function.
NOT SURE IF THAT'S WHAT THE QUESTION WANTS.