The sum of 3 consecutive odd numbers is 51 what is the second number in this sequence?

second number= 17

Step-by-step explanation:

first number=a

second number=b

third number = c

we have:

a+b+c=51  equation 1

a=2n+1     equation 2

b=2n+3    equation 3

c=2n+5     equation 4

using equations 2, 3 and 4 in equation 1, we have

2n+1+2n+3+2n+5=51

6n+9=51

6n=51-9

6n=42

n=42/6

n=7

so we have

a=(2*7)+1 =15 first number

b=(2*7)+3 =17 second number

c= (2*7)+5 =19 third number

step-by-step explanation:

we have

using a graphing tool

see the attached figure

this is a quadratic equation (vertical parabola) open up

the vertex is a > vertex

the domain of the function is all real > interval (-∞,∞)

the range of the function is the > [-6.125,∞)

the function has two x->   and

the function is increasing over the > (0.25,∞)

the function is decreasing over the > (-∞,0.25)