Answer:
a) Josh likely made the negative and positive multiplication error.
b) -20a-8+12b
= -4(5a+2-3b)
Step-by-step explanation:
To check if you are correct, you can always simplify it again:
-4(5a+2-3b)
=-20a-8+12b
Remember: 
Negative times negative equals to positive, negative times positive equals to negative!
I hope this is helpful! :)
 
        
             
        
        
        
In order to graph these, you need to understand the X and Y axis.
The X-Axis contains the first number in your ordered pair, and goes left, right (horizontally) for example the first ordered pair you have. 
(2,5 1/2). To do this, move 2 spaces to the right on your X-axis. now go 5 and a half spaces up, and plot the point. 
(-2 1/2, 0.5) For this one, you move 2 and a half spaces to the left on the X-axis, and half a space up. put a point there.
(3.5, -4 1/2) move 3 and a half spaces to the right on your X-axis, and go 4 and a half spaces down. put a point there.
let me know if you have questions! :)
        
             
        
        
        
About 68.5. Hope this helps :)
        
             
        
        
        
Let
v-------> <span> the volume of a sphere
s-------> t</span><span>he surface area of the sphere
r------> </span><span>the radius of the sphere
we know that
v=(4/3)*pi*r</span>³-----> v=(r/3)*4*pi*r²------> equation 1
and
S=4*pi*r²-----> equation 2
substitute equation 2 in equation 1
so
v=(r/3)*4*pi*r²-------> v=(r/3)*s
the answer is
the equation that <span>represents the relationship between these three measures
</span> v=(r/3)*s