Answer:
(4x+5)(-3x-1) = -12x²-19x-5
Option A:
    (-16x² + 10x - 3) + (4x² - 29x - 2) = -12x²-19x-5
    Option A is correct.
Option B:
    3(x - 5) - 2(6x² + 9x + 5) = -12x²-15x-25
    Option B is wrong.
Option C:
    2(x - 1) - 3(4x² + 7x + 1) = -12x²-19x-5
    Option C is correct.
Option D:
    (2x² - 11x - 9) - (14x² + 8x - 4) = -12x²-19x-5
    Option D is correct.
 
        
             
        
        
        
Answer:
Simple sum. The symbol Σ (sigma) is generally used to denote a sum of multiple terms. This symbol is generally accompanied by an index that varies to encompass all terms that must be considered in the sum.
 
 
        
             
        
        
        
Answer:option C is the correct answer.
Step-by-step explanation:
When the ladder leans against the wall, it forms a right angle triangle with the wall. The length of the ladder becomes the hypotenuse of the right angle triangle. 
Since the length of the ladder is 12 foot, then
Hypotenuse = 12 foot
The angle formed by the ladder with the ground is 75.5 degrees. Therefore, the height, y which is the distance from the point where the ladder touches the wall to the foot of the wall becomes the opposite side. It would be determined by applying trigonometric ratio
Sin θ = opposite side/hypotenuse
Sin 75.5 = y/12
 
        
             
        
        
        
3,500 m so 3 km and 500 m