Some of the steps in the derivation of the quadratic formula are shown.

Step 3: –c + StartFraction b squared Over 4 a EndFraction = a(x squared + StartFraction b Over a EndFraction x + StartFraction b squared Over 4 a squared EndFraction)

Step 4a: –c + StartFraction b squared Over 4 a EndFraction = a(x + StartFraction b Over 2 a EndFraction) squared

Step 4b: negative StartFraction 4 a c Over 4 a EndFraction + StartFraction b squared Over 4 a EndFraction = a(x + StartFraction b Over 2 a EndFraction) squared

Which best explains or justifies Step 4b?

A. factoring a polynomial
B. multiplication property of equality
C. converting to a common denominator
D. addition property of equality

21.4 i did it already for s1

step-by-step explanation:

the correct answer is b. negative exponential growth.

step-by-step explanation:

you can tell it's an exponential function because it decreases rapidly then levels out and never touches the x-axis.

it is negative because the y-axis decreases as the x-axis increases.

therefore it is a negative exponential growth graph.

hope i !

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 ☺

the car was traveling 40 mph before it started skidding. ( 2 points ) 17. was the driver were her brakes working at 75% efficiency or better? ( 2 points ) yes 29.

step-by-step explanation: