Part A: c for cost. c=0.31m+0.5
0.31m is the cost per minute. 0.5 is cost per call.
Part B: 0.31m+0.5=5.15 to solve we must rearrange.
subtract 0.5 from each side giving us 0.31m=4.85
divide by 0.31 giving us m=15.65
Answer:
EF = 58
Step-by-step explanation:
From the question given, we obtained the following information:
DF = 9x – 39
DE = 47
EF = 3x + 10
EF =?
We'll begin by calculating the value of x.
This can be obtained as follow:
DF = DE + EF
DF = 9x – 39
DE = 47
EF = 3x + 10
DF = DE + EF
9x – 39 = 47 + 3x + 10
9x – 39 = 47 + 10 + 3x
9x – 39 = 57 + 3x
Collect like terms
9x – 3x = 57 + 39
6x = 96
Divide both side by 6
x = 96/6
x = 16
Finally, we shall determine the value of EF as follow:
EF =?
x = 16
EF = 3x + 10
EF = 3(16) + 10
EF = 48 + 10
EF = 58
Answer:
Ambos cometas coincidirán en 2016.
Step-by-step explanation:
(The following exercise is presented in Spanish and for such reason explanation will be held in that language).
Sean 
y 
los años en los que se hacen visibles los cometas, respectivamente. Se sabe que los cometas coinciden cuando se pueden ver el mismo año, ese año estaría asociado al mínimo común múltiplo de ambos intervalos de tiempo, el cual sería igual a 72 años. Entonces, ambos cometas volverán a coincidir en 2016.
the school is at 0, and Anna's house would be at 2.5 because it is east (to the right of 0) and Ben's would be -2 (because it is west...to the left of 0)
Answer:
-5<x<9
Step-by-step explanation:
Within a triangle, the greater an angle, the greater the length of opposite side. So, since we know that 42° gives an opposite side of 23, and (3x+15)° gives an opposite side of 21, (3x+15) must be less than 42:
3x+15<42
3x<27
x<9
We also know that the angle (3x+15)° cannot equal zero or less than zero. So find x when 3x+15=0, and note that our value for x must be greater than this:
3x+15=0
3x=-15
x=-5
so, -5<x
Put both parts together to get: -5<x<9
