That would be the third option
        
             
        
        
        
Answer: 
84.80 
Step-by-step explanation: 62.72+22.08=84.80
 
        
                    
             
        
        
        
Answer:
12 feet
Step-by-step explanation:
As a  ladder is leaning against a house, it forms right angle triangle. And for right angleΔ, we use Pythagoras theorem.i.e
P²+B²= H²
Where, 
'P' is perpendicular i.e the distance  from the top of the ladder to the ground
'B' is base i.e be the distance from the bottom of the ladder to the house
'H' is hypotenuse i.e 13 
considering 'x' as perpendicular
So, base would be 'x-7'
Applying Pythagoras theorem,
x² + (x-7)²= 13²
x² +x² -14x +49 =169
2x² -14x -120= 0
x² -7x -60=0 ----> solving the quadratic equation
x² + 5x -12x-60=0
x(x+5) -12(x+5)=0
Either : x+5=0 => x=-5
OR: x-12=0 => x=12
We'll choose the positive length.
therefore , The distance from the bottom of the ladder to the house is 12 feet
 
        
             
        
        
        
Answer: division property of equality 
Step-by-step explanation: 
8x = 80
You divide the number with the letter you are trying to find (x) on both sides, so 8 divided by 80, you get 10.