Answer:
see explanation
Step-by-step explanation:
the n th term of an arithmetic sequence is
 =
 =  + (n - 1)d
 + (n - 1)d
given  = 3 and
 = 3 and  = 10, then
 = 10, then
 = 3 + d = 10 ⇒ d = 10 - 3 = 7
 = 3 + d = 10 ⇒ d = 10 - 3 = 7
 = 3 + 7(n - 1) = 3 + 7n - 7 = 7n - 4
 = 3 + 7(n - 1) = 3 + 7n - 7 = 7n - 4
the sum to n terms of an arithmetic sequence is
 =
 =  [2
[2 + (n - 1)d ]
 + (n - 1)d ]
                         =  [(2 × 3) + 7(n - 1) ]
[(2 × 3) + 7(n - 1) ]
                         =  (6 + 7n - 7 )
(6 + 7n - 7 )
                         =  (7n - 1)
(7n - 1)
                         =  n² -
 n² -  n
 n
 
        
             
        
        
        
Answer:
Step-by-step explanation:
Increasing the side length by 5 is represented as s + 5. To get the area of a square we multiply side times side: 
The area of a square is s². If we are increasing this area s² by 895, then to represent this we have s² + 895. 
Put that together into an equation:
 and simplify to
 and simplify to
10s = 870 so
s = 87
Let's check that. The area before the addition to the side is 87*87 = 7569; the area after the addition of 5 cm is 92*92 = 8464. The difference is
8464 - 7569 = 895 so we did good!
 
        
             
        
        
        
Answer:
wouldnt it be -9 
Step-by-step explanation:
beacuse negitive 7-2 is negitive 9 bc negitive plus a negitive is a negitive ?? right 
 
        
             
        
        
        
Answer:
40,60,80
Step-by-step explanation:
2x+3x×4x=180
 9x=180
 x=20
 2x=40
 3x=60
  4x=80
 
        
             
        
        
        
Step-by-step explanation:
ask for what, if you need help you