Find the 4th term of (x+5)^7

a. 35x^4

b. 4375x^4

c. 21,875x^3

d. 625x^4

B. 4375x^4

Step-by-step explanation:

Firstly, you can just multiply it and look at the fourth term or use the binomial theorem. Either way it's B.

4375x^4.

Step-by-step explanation:

There is a useful formula for answering these type of questions. It is:

(r + 1)th term of (x + a)^n = nCr x^(n-r) a^r.

4th term = (3 + 1)th term of (x + 5)^7

=  7C3 x^(7-3) 5^3

= 35 x^4 * 125

= 4375x^4.

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8

an = 22 + (n-1) *6

110 seats

step-by-step explanation:

an=a1+(n-1)(d)

a1 = 22   this is the first item in the sequence

d =6   this is how the sequence goes up

a)   an = 22 + (n-1) *6

b) a12 = 22 + (12-1) *6

    a12 = 22+11*6

  a12 = 22 +88

  a12 = 110