Answer:
x = -1
Step-by-step explanation:
y = 5 is a horizontal line
It's perpendicular would be a vertical line of the form:
x = a
Since it passes through (-1,-3)
a = -1
Hence line is: x = -1
 
        
             
        
        
        
At most means less than or equal to:
7 + x ≤ 20
 
        
             
        
        
        
Answer:
 x = 2
Step-by-step explanation:
f(x) = x + 8 
f(x) = 10
10 = x + 8 
 minus 8 from the both sides 
10 - 8 = x 
2 = x 
x = 2