Please help ASAP 40 pts

50

Step-by-step explanation:

Equilateral triangles have angles that all measure the same

180/3 = 60

so all angles measure 60

<c = 60

60 = x+10

Subtract 10 from each side

60-10 = x+10-10

x=50

The answer to your question is   x = 50

Step-by-step explanation:

Data

Equilateral triangle

∠C = x + 10

Process

To solve this problem we must consider these facts about triangles

- The sum of the internal angles in a triangle equals 180°

- All the angles in an equilateral triangle measures the same,

Equations

                    ∠A + ∠B + ∠C = 180°

but

                    ∠C + ∠C + ∠C = 180°

-Simplification

                                    3∠C = 180°

-Substitution

                                3(x + 10) = 180°

-Expand

                                3x + 30 = 180°

-Solve for x

                                3x = 180 - 30

                                3x = 150

                                  x = 150/3

                                  x = 50

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 ☺