Answer:
S=157
Step-by-step explanation:
an= a1+(n-1)d
a2=80+(2-1)(-3)
a2=80-3
a2=77
Sn=(a1+an)*n/2
S2=(80+a2)*2/2
S2=(80+77)*1
S2=157
 
        
             
        
        
        
Answer: 5
This is because (4r + 6) means you take r and multiply that number by 4. 
Because there is no number, r would equal one in this case. 
4 • 1 is 4 
4 + 6 is 10
This would give us 1/2(10)
Half of 10 is 5. 
Therefore, the answer is 5.
        
             
        
        
        
Isolate the m, go backwards for PEMDAS.
C = 2m + d
C (-d) = 2m + d (-d)
C - d = 2m
(C - d)/2 = 2m/2
m = (C - d)/2
m = (C - d)/2 is your answer
hope this helps
 
        
             
        
        
        
Answer:x=3 y=1/2
Step-by-step explanation:
x+2y=4
2x-2y=5
Add both equations together 
x+2x+2y-2y=4+5
3x+0=9
3x=9
Divide both sides by 3
3x/3=9/3
x=3
Substitute x=3 in x+2y=4
x+2y=4
3+2y=4
Collect like terms 
2y=4-3
2y=1
Divide both sides by 2
2y/2=1/2
y=1/2
 
        
             
        
        
        
Answer:
16.4 m²
Step-by-step explanation:
length = 4.6 m
breadth = 360 cm = 360 ÷ 100 = 3.6 m
Perimeter = 2*(l + b)
                  = 2 * ( 4.6 + 3.6)
                  = 2 * 8.2
                   = 16.4 m²