Remark
You have 40 dollars to spend.
<em><u>AT & T</u></em>
Let the number of minutes = M
A. 20 + 0.10*M ≤ 40
B. 20 + 0.10*M ≤ 40 Subtract 20 from both sides.
20 - 20 + 0.10M ≤ 40 - 20
0.10M ≤ 20 Divide by 0.10
0.10M/0.10 ≤20/0.10
M≤ 200 minutes.
Verizon
A
15 + ( M ≥ 300)*0.50 ≤ 40
B
15 + ( M ≥ 300)*0.50 ≤ 40 Subtract 15 from both sides.
(M≥300)*0.50 ≤ 25
(M≥300) ≤ 50 minutes.
This last one is a good deal more complicated. What it means is that if you are under 300 minutes, you pay only 15 dollars. If you are over 300 minutes, you can only go 50 more minutes before over extend your budget.
Part C
These are alike in that they have a flat rate associated with them and both have a budgeted amount that has to be obeyed.
They are quite different in what they offer. The second plan is for people who use their cell phone quite a bit. For people like us (emergency only), the first plan is much better. We would always be within our 40 dollar limit. We don't use our cell but maybe 10 - 15 minutes a month on average.
Part D
I can't answer this for you. It depends on where you live and who offers you the best coverage. I would pick the first one, but that doesn't mean that it would be best for you.
The general formula to form a parabole equation is written below.
y = a(x - h)² + k
with (x,y) is one of the points lies on the parabola, and (h,k) is the vertex of the parabola.
From the question above, we get this information
(x,y) = (5,24)
(h,k) = (4,9)
The remaining value to find is a. We need to find the value of a to form the equation. Input the numbers to the equation.
y = a(x - h)² + k
24 = a(5 - 4)² + 9
24 = a(1) + 9
24 = a + 9
24 - 9 = a
a = 15
Write the equation, without inputing the value of x and y
y = a(x - h)² + k
y = 15(x - 4)² + 9
<em>This is the equation</em>
<span>1=<span>ln<span>(<span>x+4</span>)</span></span></span><span><span>ln<span>(<span>x+4</span>)</span></span>=1</span><span><span>ln<span>(<span>x+4</span>)</span></span>=1</span><span><span>e<span>ln<span>(<span>x+4</span>)</span></span></span>=<span>e1</span></span><span><span>x+4</span>=<span>e1</span></span><span><span>x+4</span>=2.718282</span><span><span><span>x+4</span>−4</span>=<span>2.718282−4</span></span><span>
x=<span>−<span>1.281718</span></span></span>
Answer:
You could solve this by taking the y value and adding it to the multiplied rate.
For example: For Jill's 6 year mark, the equation would be 11(6) + 15.
Hope this makes sense, don't hesitate to ask for clarification on a certain part of the answer.
