the sum of three consecutive even number is 60 . find the smaller number
answer it step by step
Answers
Answer:
Let 2n = the smallest consecutive even number.
Let 2(n + 1) = 2n + 2 = the next consecutive even number, and ...
Let 2(n + 2) = 2n + 4 = the third consecutive even number.
Since the sum of these 3 consecutive even numbers is 60, we can write the following equation:
2n + (2n + 2) + (2n + 4) = 60
2n + 2n + 2 + 2n + 4 = 60
By the Commutative Property of Addition, i.e., a + b = b + a, we have on the left side of the equation:
2n + 2n + 2n + 2 + 4 = 60
Now, collecting like-terms on the left side, we get:
(2 + 2 + 2)n + 6 = 60
(6)n + 6 = 60
6n + 6 = 60
Now, in order to solve for n, we begin isolating n on the left side of the equation by subtracting 6 from both sides:
6n + 6 - 6 = 60 - 6
Step-by-step explanation:
Let the first even number be a .
So, the 3 consecutive numbers will be a , a+2 , a+4
Sum of the 3 consecutive even numbers = 60
So here a , a+2 , a+4 form an A.P.
therefore, here first term(A) = a
difference (d) = a+2 - a
d=2
and Sn = 60
we know Sn = n/2 * 2a + {n-1}d
putting the values
Sn = 3/2 * 2a + 4 [sn=60]
60 = 3/2 * 2a + 4
120 = 3 * 2a +4
40-4 = 2a
36 = 2a
a= 18
So the smaller number is 18