I X+ 1/X = 5 then show that x^2+ 1/x^2 =23

Explanation :

⇒ (x + 1/x) = 5.

As we know that,

Squaring on both sides of the equation, we get.

⇒ (x + 1/x)² = (5)².

As we know that,

☢︎︎Formula of:

⇒ (a + b)² = a² + b² + 2ab.

Using this formula in the equation, we get.

⇒ (x)² + (1/x)² + 2(x)(1/x) = (5)².

⇒x²+1/x² + 2 = 25.

⇒ x² +1/x²= 25 - 2.

⇒ x² +1/x² = 23.

Hence Proved.✅

16.9 times 2.85

step-by-step explanation:

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 ☺