Answer:
23
y = ----- (x + 1)^2 - 3
9
Explanation:
Use the general vertex form equation of the parabola to find the function.
1) Vertex form equation: y = A (x - h)^2 + k
Where h and k are the vertex - coordinates, i.e. vertex = (h,k)
2) The vertex is the minimum (or maximum) of the parabola. In this case it is (-1,-3)
=> h = -1, k = -3.
3) Replace the vertex-coordinates in the vertex form equation of the parabola:
y = A(x + 1)^2 - 3
4) To find A replace the coordinates of the other point given: (2,20)
=> 20 = A(2 + 1)^2 - 3
=> A(3^2) = 20 + 3
=> A(9) = 23
=> A = 23/9
5) Replace h, k and A in the vertex form of the parabola:
y = (23/9) (x + 1)^2 - 3
Answer: 4 Notebooks
Step-by-step explanation:
The number of notebooks is x, the number of markers is 2x+3.
Since the price per notebook is $5 we can write it as 5x, And the price per marker is $2, we can write that as 4x+6
5x+4x+6=42
9x=36
x=4
so he bought 4 notebooks and 11 markers.
CHECK: 4*5=20 and 11*2=22 20+22=42
Note that when rounding, if the number is:
5 or greater, round up
4 or less, round down
43.68532 rounded to the nearest dollar is 44, as 6 rounds up
$44 is your answer
hope this helps
Hmmm..... let us try again...but this time with a different strategy,.... by the graph method.
The system is
3x + 4y =96
2x + 5y = 99.
We find solutions of each system and then plot them on a graph.
Solutions for equation 1 = (2, 22.5) and (30, 0)
Solutions for equation 2 = (49.5 , 0) and (1, 19.4)
Now, we plot both the equations on a graph paper and note its intersecting point.
Experimentally, we find the intersecting point is (12,15)
Thus, the solution for the system is x = 12 , y = 15.
Thus, we arrive at the conclusion 1 shirt costs 12$
1 cap costs 15$