The trestle meets the ground at __ units and __ units

The answer to this for the first box is 0.9 and the second box 9.1

0.9 and 9.1

Step-by-step explanation:

The quadratic function y = -x2 + 10x - 8 models the height of a trestle on a bridge. The x-axis represents ground level.

To find where the section of the bridge meets ground level, solve 0 = -x2 + 10x - 8.

Where does this section of the bridge meet ground level?

Choose an equation that would be used to solve  0 = -x2 + 10x – 8

(x + 25)2 = –8

(x – 5)2 = 17  (This is the correct choice for the first part of the question.)

(x – 10)2 = 25

Solve the equation to find where the trestle meets ground level. Enter your answers from least to greatest and round to the nearest tenth.

The trestle meets the ground at  

.9

units and  

9.1

units.

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 ☺

146

step-by-step explanation: