Answer:
a. Plan B; $4
b. 160 mins; Plan B
Step-by-step explanation:
a. Cost of Plan A for 80 minutes:
Find 80 on the x axis, and trave it up to to intercept the blue line (for Plan A). Check the y axis to see the value of y at this point. Thus:
f(80) = 8
This means Plan A will cost $8 for Rafael to 80 mins of long distance call per month.
Also, find the cost per month for 80 mins for Plan B. Use the same procedure as used in finding cost for plan A.
Plan B will cost $12.
Therefore, Plan B cost more.
Plan B cost $4 more than Plan A ($12 - $8 = $4)
b. Number of minutes that the two will cost the same is the number of minutes at the point where the two lines intercept = 160 minutes.
At 160 minutes, they both cost $16
The plan that will cost less if the time spent exceeds 160 minutes is Plan B.
Answer:
8,920 ÷ 80=111.5
892 ÷ 8=111.5
89.2 ÷ 0.08=111.5
.892 ÷ 0.008=111.5
Step-by-step explanation:
Where p is the distance the focus is above the vertex, the equation of a parabola with vertex (h, k) can be written as
... y = 1/(4p)·(x -h)² +k
The vertex is halfway between the focus and directrix. The focus of your parabola is on the y-axis at y=6, and the directrix of your parabola is at y=-6, so the vertex of your parabola is on the y-axis at y=0. That is, the vertex is
... (h, k) = (0, 0).
The distance p from the focus at y=6 to the vertex at y=0 is 6 units, so
... p = 6.
Filling these values into the equation gives
... y = 1/(4·6)·(x -0)² +0
... y = (1/24)x²
Answer:
x = 19, y = 1
Step-by-step explanation:
f(x) = 5(x + 4) - 6
y = 5(x + 4) - 6
inverse function:
switch x and y
x = 5(y + 4) - 6
solve for y
x = 5y + 20 - 6
x = 5y + 14
x - 5y = 14
-5y = -x + 14
y = (-x + 14)/-5
y = 1/5x - 2.8
plug 19 in for x
y = 1/5(19) - 2.8
y = 3.8 - 2.8
y = 1
Answer:
2.4
Step-by-step explanation: 387 divided by 161.25 equals 2.31 which means it would take 2.4 months to fully pay off her brother.
