Solve the equation (-4) + (-1) + 2 +.........+x=437 (ARITHMETIC PROGRESSION)
Answers
Answered by
3
Answer:
n= 19 an x = 50
Step-by-step explanation:
Sn = 437
An = x
A = -4
D = -1-(-4)= -1 +4= 3
now, An = A + (n-1)D
x = -4 + ( n-1)3
x = -4 + 3n - 3
x = 3n - 7 .......(1)
and Sn = n/2 ( A+ An)
Sn= n/2 ( -4 + x)
437= n/2 ( -4 + 3n - 7 ) { by equation (1)}
437*2= n ( 3n-11)
874 = 3n^2 - 11n
3n^2 - 11n - 874 = 0
b^2-4ac
(-11)^2- 4*3*(-874)
121+10488
10609
now n= -b±√b^2-4ac/2a
n = -(-11)±√10609/2*3
n= 11 ±103/6
when +; n= 11+103/6
n= 114/6 ⇒ 19
and when - ; n= 11- 103/6
n= -92/6 not divisible by 6 and it is negative so this is not acceptable
hence in equation (1), n=19
so x= 3*19 -7
x= 57- 7
x= 50
Answered by
0
See this attachment
This is the best possible answer
Attachments:
Similar questions