Xpand.
necessary. combine e terms
(2x+ 5)(2x-5)

4x²−25

Explanation:

(2x+5)(2x−5)

=(2x+5)(2x+−5)

=(2x)(2x)+(2x)(−5)+(5)(2x)+(5)(−5)

=4x²−10x+10x−25

=4x²−25

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

b

step-by-step explanation: