Answer:
third option
Step-by-step explanation:
Given
x² + 4x - 4 = 0 ( add 4 to both sides )
x² + 4x = 4
Using the method of completing the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 4 + 4, that is
(x + 2)² = 8 ( take the square root of both sides )
x + 2 = ± = ± 2
( subtract 2 from both sides )
x = - 2 ± 2
Given:
The first two terms in an arithmetic progression are -2 and 5.
The last term in the progression is the only number in the progression that is greater than 200.
To find:
The sum of all the terms in the progression.
Solution:
We have,
First term :
Common difference :
nth term of an A.P. is
where, a is first term and d is common difference.
According to the equation, .
Divide both sides by 7.
Add 1 on both sides.
So, least possible integer value is 30. It means, A.P. has 30 term.
Sum of n terms of an A.P. is
Substituting n=30, a=-2 and d=7, we get
Therefore, the sum of all the terms in the progression is 2985.
Answer:
7
Step-by-step explanation:
7 is approximate to because 7 is
, and 49 is close to 47