Anything (except 0) to the 0 power is equal to 1.
8^0  = 1
(-8)^0 = 1
24781297429879741^0 = 1
 
        
             
        
        
        
Y=-5x+9
3x+2(-5x+9)=4
3x-10x+18=4
-7x=4-18
-7x=-14
x=2
5(2)+y=9
10+y=9
y=9-10
y=-1
The answer is (2,-1) :)
        
                    
             
        
        
        
2 and 12 both correspond with angle 5
        
                    
             
        
        
        
If you flip a coin one time, the probability to get a Head is 
p = 1/2
The probability of not getting a head in a single toss is :
q = 1 - 1/2 = 1/2
Thus there is only one unique situation to get the same number of heads and tails : in 10 toss you need to get exactly five heads, it will means that the rest is the tails.
Now using Binomial theorem of probability, the probability of getting exactly x = 5 heads in a total of n = 10 tosses is :
P(X = 5) =  ≈ 0.246
≈ 0.246
So the probability of that is 24,6 %
Good Luck