Answer:
250
Step-by-step explanation:
85% · n = 212.5
[convert 85% to .85]
.85n = 212.5
n = 212.5/.85
n = 250
 
        
             
        
        
        
Answer: 
The value of r=
The value of x=
Step-by-step explanation:
Given that,
A) 
Now,

8(2r-2)=9(7r+10)
16r-16=63r+90
-16-90=63r-16r
-(16+90)=47r
-106=47r
r=
B) 
Now,

5(x+5)=9[3(x-2)-1]
5x+25=9[3x-6-1]
5x+25=9[3x-7]
5x+25=27x-63
25+63=27x+5x
83=32x
x=
 
        
             
        
        
        
So we want to know which of the following functions has an inverse function. So an inverse function is a function that "reverses" another function. We need to put y instead of x and x instead of y. So for the first case: y=x is x=y so this function has an inverse function. y=x^2 is x=y^2 so y=sqrt(x). y=x^3 is x=y^3 so y=∛x. y=x^4 so x=y^4, y=4√x or forth root of x. So all of our functions have an inverse function. 
        
             
        
        
        
I’ll answer this in a second