Explanation:
We usually use graphs to solve two linear equations in two unknowns.
The basic idea is that a graph of an equation is the pictorial representation of all of the points that satisfy the equation. So, where the graph of one equation crosses the graph of another, the point where they cross will satisfy both equations.
Finding a solution means finding values of the variables that satisfy all of the equations. Hence, the point of intersection is the solution of the equations.
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To solve linear equations by graphing, graph each of the equations. Then find the coordinates of the point where the lines intersect. Those coordinates are the solution to the equations.
If the solution is not at a grid point on the graph, determining its exact value may not be easy. This can often be aided by a graphing calculator, which can often tell you the point of intersection to calculator accuracy.
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If the lines don't intersect, there are no solutions. If they are the same line (intersect everywhere), then there are an infinite number of solutions.
 
        
             
        
        
        
Answer:
Sampling is necessary because researchers in the social sciences almost never have enough resources — time or money — to collect information about the entire set of subjects of interest to them.
Step-by-step explanation:
Sampling is done because you usually cannot gather data from the entire population. Even in relatively small populations, the data may be needed urgently, and including everyone in the population in your data collection may take too long.
 
        
             
        
        
        
I've attached a photo of the solution below. Hope it helps!
 
        
             
        
        
        
Answer: the result is 930 minutes.
Step-by-step explanation:
15.5 hours to minutes has been calculated by multiplying 15.5 hours by 60
 
        
             
        
        
        
Answer:
From the given figure we can see that :---
MN||PO, MN=PO and MP=NO
Therefore, angle M=angle N (adjacent sides of the trapezoid)

angle M=angle N= (6×18)+20=108+20 =128°
angle O =(180°-128°)=52°
<h3>Hence, angle O is <u>52°.</u></h3>