Answer:
B
Step-by-step explanation:
The black graph is the graph of y=f(x).
The red graph is the reflection of the black graph across the y-axis.
A.
determines the translation of the graph
one unit to the right.
B.
determines the reflection of the graph
across the y-axis.
C.
determines the translation of the graph
one unit up.
D.
determines the reflection of the graph
across the y-axis.
Answer:
387 contains 80 and 8 x 10 = 80
Assuming that the cost per minute is the same for both months and the plan fee is the same, you can use y=mx+b for this
y is the cost of the phone plan, x is the cost per minute and b is the start cost.
so 19.41=25x+b for the first month
and 45.65=380x+b for the second month
solve both for b you get:
19.41-25x=b and 45.65-380x=b. from this we get
19.41-25x=45.65-380x
solve for x
328x=26.24 and x=0.08
this means the cost per minute is 0.08c/min (answer A)
rewrite the equation to calculate b, and where this time, the x is the number of minutes talked.
y=0.08x+b and plug in one of the two months
45.65=0.08 * 380 + b
Solve for b and b is 15.25
so the final equation is
y=0.08x+15.25 (answer B)