Answer:
y = -2(x -1)^2 -2
Step-by-step explanation:
My "work" consists of providing a table of values to a calculator and asking it for a quadratic model. The result is ...
y = -2(x -1)^2 -2
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If you like to do these "by hand", you can write the model, then solve for its parameters using the given points.
We observe that the first and third points have the same y-coordinate. Then the vertex of the quadratic will be halfway between the corresponding x-values, at ...
h = (-2 +4)/2 = 1
So, one of the parameters of the model is found already. Using the second point and one other, we can find the remaining parameters for our model:
y = a(x -1)^2 +k
for (4, -20) ...
-20 = a(4 -1)^2 +k = 9a +k
for (0, -4) ...
-4 = a(0 -1)^2 +k = a + k
Subtracting the second equation from the first, we get
-16 = 8a
-2 = a . . . . . divide by 8
Substituting this value of a into the second equation, we have ...
-4 = -2 +k
-2 = k . . . . . . add 2
So, our model is ...
y = -2(x -1)^2 -2
Let L represent the number of ribbons Lily has and D be the amount of ribbons Dora has.
Since Lily has 4 fewer ribbons than Dora, the amount of ribbons Lily has can be represented as this:
L = D - 4
Because Lily has 7 ribbons, you can plug in 7 for L:
7 = D - 4
When you solve for the amount of ribbons Dora has (D), which is done by adding 4 to both sides, you get D = 11.
Therefore, Dora has 11 ribbons.
Use Slader it always has the answers for textbook question -I hope this helps!
Answer:
2.5 ft/hr Step-by-step explanation: divide the number of hours by the number of feet.
Step-by-step explanation:
First line: 37, 77
Second line: 28, 82