HELP ME PLEASE IM CONFUSED

A.) 2(20x8)+2(15x20)=920

B.) 120 mm sq

C.) 1160 mm sq

Step-by-step explanation:

Starting with A.)

okay so basicly what they are asking you to do is find the area of each faces except for the bases. since a rectangular prisim has equal parallel faces, they tell you to multiply the the area of one to find the other parallel face.

Now B.)

it is just telling you to find the area of ONE base so that one is fairly simple.

And lastly C.)

for C, all you are doing is doubling B since we only found the area for one base, and adding A's answer to it to find your total surface area.

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺

something over 10 so ? /10

step-by-step explanation: