A marching band is arranged in rows of 7 the first row has 3 band members and each row after the first has 2 more band members than the row before it write a rule for the number of band members in the nth row. Then find the total number of band members.

= 1+2n and 63

Step-by-step explanation:

the question belongs to arithmetic sequence and can be determined by the formula

= a1 + d (n-1)

Let " " represents the number of band members in the nth row

and 'd' represents the common difference.( as stated each row  has 2 more band members than the row before it)

therefore, d=2

'a1' represents first row that has three members. So, a1 = 3

->Rule for nth term will be:

= 3 + 2(n-1)

= 3 + 2n -2

= 1+2n

-> In order to find total number of band members ''

Let represent total number in n rows

We'll use the formula, i.e  = n/1 ( +  )

where, n is the number of terms, is the first term and is the last term

So,

n=7

= 1 + 2(7)= 15

=> = 7/2 (3 + 15)

= 63

The total number of band members are 63

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2

answer: '

the distance between points l and m

step-by-step explanation: