Answer:
-2y +2
Step-by-step explanation:
(x - y + 1) - (x + y - 1)
Distribute the minus sign
(x - y + 1) - x - y + 1
Combine like terms
x-x -y-y +1+1
-2y +2
 
        
                    
             
        
        
        
The GCF of 12, 21, and 30 is 3.
The factors of 12 are: 1, 2, 3, 4, 6, 12
<span>The factors of 21 are: 1, </span>3, 7, 21
<span>The factors of 30 are: 1, 2, </span>3, 5, 6, 10, 15, 30
<span>Then the greatest common factor is 3.
</span>
The GCF of 11, and 44 is 11. 
The factors of 11 are: 1, 11
The factors of 44 are: 1, 2, 4, 11, 44
Then the greatest common factor is 11. 
Hope this helps.
        
                    
             
        
        
        
Volume=height times area of base
base=circle so area of base=pir^2
ok so solume=height times pi times r^2
1.
thermos, h=10, r=2
therefor 
 volume=10pi2^2=
 volume=10pi4=
40pi in^3 is brought to school
2. inside is 4 inches deep
h=4, r=1.5
volume=4pi1.5^2
volume=4pi2.25
volume=9pi
answer is 9pi in^3
3. so find 80% of 9pi
80%=0.8
0.8 times 9pi=7.2pi in^3
each times is 7.2pi in^3
4. ok so this is assuming that you fill the mug to 80% (7.2pi) each time and the remainder is it less or more or equal to half of 7.2pi so 
total in thermos=40pi
each pour=7.2pi
40pi-7.2pi-7.2pi-7.2pi-7.2pi-7.2pi=4pi
is 4pi more or less than 7.2pi
7.2pi/2=3.6pi
4pi>3.6pi
it is MORE
1. 40pi in^3
2. 9pi in^3
3. 7.2pi in^3
4. MORE than half
 
        
             
        
        
        
Parallel Lines lie within the same plane but never intersect
Hope this helps!