ANSWER
93 and 70
EXPLANATION
We have that one number is 23 more than another.
Let the first number be x.
Let the second number be y.
This means that:
x = 23 + y ____(1)
The sum of the two numbers is 163. This means that:
x + y = 163 ____(2)
Put (1) in (2):
23 + y + y = 163
23 + 2y = 163
2y = 163 - 23
2y = 140
y = 140 / 2
y = 70
From (1):
x = 23 + 70
x = 93
The two numbers are 93 and 70.
 
        
             
        
        
        
Answer:
$8.50
Step-by-step explanation:
multiply 0.50 by 11 to get 5.5 and then add the 3 dollars from the ice cream to get 8.5 - make sure to change 8.5 to $8.50 
 
        
                    
             
        
        
        
They are perpendicular because when you change 2x+8y=16 to slope intercept form it becomes y= -1/4x+2 and the slope (-1/4) is the negative reciprocal of 4, which is the slope for your other equation. 
Please comment if you have any questions :)