Answer:
Martina is 53 inches tall.
Step-by-step explanation:
In order to write an expression that relates the siblings heights we need to attribute variables to each brother. First we will call Martina's height as "m", then we can call her little brother's height as "b". The problem states that Martina's height is 3 inches less than twice the height of her brother so we have:
m = 2*b - 3
Then the problem gives us the height of her brother that is 28 inches tall, so b = 28. We can now compute Martina's height:
m = 2*28 - 3 = 56 - 3 = 53 inches.
Answer:

Step-by-step explanation:
Let
denotes number of pencils, markers, erasers respectively.
For Andrea:

For Justin:

For Virginia:

On subtracting equations (i) and (ii), we get

Put
in equation (i)

Put
in equation (iii)

Multiply equation (iv) by 5 and equation (v) by 6 and then subtract both the equations.

Put
in equation 

Put
in equation (i)

Answer:The set fee would be $15
Explanation:The set fee is the starting value. This means that it is the value of the y at x = 0 (y-intercept).
To get the set fee, we would first need to get the equation of the line.
Equation of the linear line has the following general formula:
y = mx + c
where m is the slope and c is the y-intercept
1- getting the slope:we are given two points which are:
(20,25) and (50,40)
the slope =

The equation now is:
y = 0.5x + c
2- getting the value of the y-intercept:To get the value of the c, we will use any of the given points, substitute in the equation and solve for c.
I will choose the point (20,25)
y = 0.5x + c
25 = 0.5(20) + c
25 = 10 + c
c = 15
The equation of the line representing the scenario is:y = 0.5x + 15
Now, we know that the value of the c is the y-intercept which is the initial value of the function at x=0.
In our situation, this represents the set fee.
Hope this helps :)
Answer: 207/4 or -51.75
Step-by-step explanation: