Answer:
900
Step-by-step explanation:
 
        
             
        
        
        
Answer:
(0,6) or 6
Step-by-step explanation:
To find the y-intercept look at the last variable you have, which in this case is 6. Glad to help :)
 
        
             
        
        
        
The solution is the point of intersection between the two equations.
Assuming you have a graphing calculator or a program to lets you graph equations (I use desmos) you simply put in the equetions and note down the coordinates of the point of intersection.
In the graph the first equation is in blue and the second in red. 
The point of intersection = the solution = (-6 , -1) 
If you dont have access to a graphing calculator you could draw the graphs by hand; 
1) Draw a table of values for each equation; you do this by setting three or four values for x and calculating its image in y (you can use any values of x) 
y = 0.5 x + 2 (Im writing 0.5 instead of 1/2 because I find its easier in this format)
 x | y 
 -1 | 1.5 * y = 0.5 (-1) + 2 = 1.5
 0 | 2 * y = 0.5 (0) + 2 = 2
 1 | 2.5 * y = 0.5 (1) + 2 = 2.5
 2 | 3 * y = 0.5 (2) + 2 = 3
y = x + 5
x | y 
 -1 | 4 * y = (-1) + 5 = 4
 0 | 5 * y = (0) + 5 = 5
 1 | 6 * y = (1) + 5 = 6
 2 | 7 * y = (2) + 5 = 7
2) Plot these point on the graph
I suggest to use diffrent colored points or diffrent kinds of point markers (an x or a dot) to avoid confusion about which point belongs to which graph
3) Using a ruler draw a line connection all the dots of one graph and do the same for the other
4) The point of intersection is the solution
 
        
        
        
First, we can see that there are four sides, and none of these equation contradict each other, so it is safe to say that <em>this is a quadrilateral</em>.
Second, all of the equations have the slope of <em>0 or undefined</em>, so it is a rectangle.
Lastly, the four points of intersection shows us that the side lengths are <em>3 and 5</em> units, so the area of it is 15 units².
 
        
                    
             
        
        
        
We round a number to three significant figures in the same way that we would round to three decimal places. We count from the first non-zero digit for three digits. We then round the last digit. We fill in any remaining places to the right of the decimal point with zeros.