The z-score is calculated by the formula (x - mu)/sigma, where x is the value, mu is the mean, and sigma is the standard deviation.
        
             
        
        
        
2X^2+22x+318=1270
2x^2+22x-952=0
x^2+11x-476=0
(x+28)(x-17)=0
x=17
        
             
        
        
        
If you would like to know how many boys play video games daily, you can calculate this using the following steps:
55% of 80 = 55% * 80 = 55/100 * 80 = 44
Result: 44 boys play video games daily.
        
                    
             
        
        
        
H + 121 + 31 = 180
H + 152 = 180
H = 180 - 152
H = 28
        
             
        
        
        
Answer:
(x,y) -> (-y,x), second option.
Step-by-step explanation:
Rotation of 90 degrees about the origin:
The rule for a rotation of a point (x,y) 90 degrees about the origin is given by:
(x,y) -> (-y,x)
This is that the question asks, and so, this is the answer, which is the second option.