Sanjay graphs a quadratic function that has x-intercepts of –3 and 7. Which functions could he have graphed? Check all that apply.

g(x) = x2 – 4x – 21
g(x) = (x – 3)(x + 7)
g(x) = 3x2 – 12x – 63
g(x) = –(x + 3)(x – 7)
g(x) = x2 + 4x – 21

Step-by-step explanation:

When r is an x-intercept of the function, (x -r) is a factor. The two given x-intercepts mean that two factors of the function are (x -(-3))(x -7). There may be a vertical scale factor that is not necessarily positive.

These factors multiply out to give ...

  (x +3)(x -7) = x^2 -4x -21 . . . . . . matches the first choice

When this expression is multiplied by 3, it matches the third choice:

  3(x +3)(x -7) = 3x^2 -12x -63

When the factored form is multiplied by -1, it matches the fourth choice:

  -(x +3)(x -7)

answer:

payment just for service  

→

$

87.12

payment for service including tax

→

$

94.09

explanation:

service only with 20% tip  

→

$

72.6

(

1

+

20

100

)

=

$

87.12

in the opening of the question the word 'service' is associated only with the pretax value.

the closing part of the question asks: how much did she pay for the  

service

−−−−−−  

so technically the answer is  

→

$

72.6

(

1

+

20

100

)

=

$

87.12

however, the intention of the question provider may have been that your answer is to be  

$

87.12

(

1

+

8

100

)

=

$

94.09

to 2 decimal places.

'

payment just for service  

→

$

87.12

payment for service including tax

→

$

94.09

tony b

mar 21, 2017

answer:

trying to explain it another way

explanation:

service charge  

.

→

$

72.60

20% tip  

20

100

×

$

72.60

=

$

14.52

−−−−−−  

←

add

$

87.12

tax  

8

100

×

$

87.12

=

$

6.97

−−−−−  

←

add

$

94.09

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