So first off, remember the formula for the area of a rectangle. it's length time width right? or, you could think that A= 2 things multiplied together. how can we simplify x^2 - x -72 to equal two things multiplied together? well, we can factor it! We know that one of the factors is x+8 right? so what's the other factor? it would be x-9. so, we know width is x-9. I'm not sure if you need an actual value for width. if so, I could probably go further.
Step-by-step explanation:
i) 

ii) 
iii) 

Answer:
f(- 2) = - 1
Step-by-step explanation:
To evaluate f(- 2) substitute x = - 2 into f(x) , that is
f(- 2) = 3 - (- 2)² = 3 - 4 = - 1
Given:
In the given triangle,
With respect to y, Perpendicular = 10 cm and Base = 8 cm
To find the value of y.
Formula
By Trigonometric Ratio we get,

Now,
Putting the values of perpendicular and base we get,

or, 
or, 
Rounding off to the nearest tenth, we have;

Hence,
The value of y is 51.3°.
Answer: 32 meters
Explanation: The 4 meter pole casts a shadow of 5 meters. The towers unknown height casts a shadow of 40 meters. Now isolate the shadows. 5 and 40. 40 divided by 5 is 8, so 4 times 8 is 32.