Answer:
infinite
Step-by-step explanation:
 
        
                    
             
        
        
        
Idk what linear combination is but you can solve this way: 
3x+y=4
-2x-y=-5
x=-1
3(-1)+y=4
-3+y=4
y=7
So x=-1 and y=7
        
                    
             
        
        
        
Answer:
I got -64
Step-by-step explanation:
The begging multiplication is 0 and subtract -7 is becomes just -7 then add 3 and it is -4 to the third power is -64
 
        
             
        
        
        
<em>Answer: C</em>
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<em>It is C because when there is a line at the top of the number, it is infinite and repeats many times. That number in a shorter was can be written as a fraction over 990. Two of the answer choices has 990 in it which is letters B and C. This eliminates answer choices A and D. The number that is within the dot is your numerator (645) and 990 is your denominator. Overall the answer is 645/990</em>