Nobody can solve this without any further information?
Answer:
<h2>D. y = 8x² + 8x + 4</h2>
Step-by-step explanation:
The equation of a linear function is in form:

We have:




Let the original 2-digit number be xy.
Because 5 times the sum of the digits is 13 less than the number, therefore
5(x + y) = 10x + y - 13
5x + 5y = 10x + y - 13
-5x + 4y = - 13 (1)
The number with reversed digits is yx.
Because 4 times the sum of the digits is 21 less than the reversed 2-digit number, therefore
4(x + y) = 10y + x - 21
4x + 4y = 10y + x - 21
3x - 6y = -21
x - 2y = -7
x = 2y - 7 (2)
Substitute (2) into (1).
-5(2y - 7) + 4y = -13
-10y + 35 + 4y = -13
-6y = -48
y = 8
From (3), obtain
x = 2*8 - 7 = 9
Answers:
The original 2-digit number is 98
The reversed 2-digit number is 89
The difference between the original and the reversed 2-digit numbers is
98 - 89 = 9
Answer:

Step-by-step explanation:
Given


![Interval: [1,8]](https://tex.z-dn.net/?f=Interval%3A%20%5B1%2C8%5D)

Required
Find c using Intermediate Value theorem
First, check if the value of M is within the given range:







M is within range.
Solving further:
We have:


Substitute 21 for f(x) in 

Express as quadratic function


Expand



or 
or 
The value of
is outside the ![Interval: [1,8]](https://tex.z-dn.net/?f=Interval%3A%20%5B1%2C8%5D)
So:



By comparison:

Have the unknown amount = x
so 3x : 9x
you know how many kids meals were bought is equal to the ratio (3x = 12, so x=4)
you already know how many X's for the adults (9) so just multiply (9x4= 36)
lastly add since you need to find the total meals bought (36+12= 48)