A store sells a package of 25 trading cards for $5.25. What is the unit price per card?

What value of x is the solution to the equation: 3x – 7 = x +1 5

Bumek [7]

Answer:

x = 11

Step-by-step explanation:

3x - 7 = x + 15 ( subtract x from both sides )

2x - 7 = 15 ( add 7 to both sides )

2x = 22 ( divide both sides by 2 )

x = 11

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2 years ago

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A new hospital tracked the number of births during its first 6 months of operation, as shown in the table. Find a quadratic func

UNO [17]

Let x refers to the Month numbers
And y refers to Number of births

There is 5 steps to find the quadratic function that models the data.

First step ⇒ Plot the data pairs (x, y) in a coordinate plane.
 which are the blue circles in the attached figure

Second step ⇒ Draw the parabola you think best fits the data.
 Which is the red function in the attached figure.

Third step ⇒ Estimate the coordinates of three points on the
 parabola, which are (2, 108), (4, 68), and (6, 75).
 which are the black squares in the attached figure

Fourth step ⇒ Substitute the coordinates of the points into the model 
 y = ax2 + bx + c
 to obtain a system of three linear equations.

 4a + 2 b + c = 108 ---------(1)
 16a + 4 b + c = 68 ---------(2)
36a + 6 b + c = 75 ---------(3)

Fifth step ⇒ Solve the linear system.
 By using the calculator
 a = 5.875 , b = -55.25 , c = 195

So, the quadratic model for the data is ⇒ y = 5.875 x²- 55.25 x + 195
============================================
To predict the number of births for month 8
substitute with x = 8 ⇒ y = 5.875 * 8²- 55.25 * 8 + 195 = 129