16x - 4 + 58 + 9x - 6 = 180
25x + 48 = 180
25x = 132
x = 5.28
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)
Answer:
It is constant from point C to point D.
Step-by-step explanation:
Sum up the total number of votes.
So, 5+7+8=20 students
Answer:
B. 2x – 1 = 13 and x = 7
Step-by-step explanation:
We are given 4 equations and a solution for each. We have to tell which of the given solution satisfies the given equation.
Option A.
2x -1 = 13 and x = 6
Using this value in the equation, we get:
2(6) -1 = 13
12 - 1 = 13
11 = 13, which is not true. Hence this option is not valid
Option B.
2x - 1 = 13 and x = 7
Using the value in the equation, we get:
2(7) - 1 =13
14 - 1 =13
13 = 13, which is true. Hence this option is valid.
Option C.
2x + 1 =13 and x = 7
Using the value in the equation, we get:
2(7) + 1 = 13
15 = 13, which is not true. So this option is not valid
Option D.
2x - 1 = 13 and x = 11
Using this value in the equation, we get:
2(11) - 1 = 13
21 = 13, which is not true. Hence this option is not valid.
