9514 1404 393
Answer:
5 hours
Step-by-step explanation:
A quick way to look at this is to compare the difference in hourly charge to the difference in 0-hour charge.
The first day, the charge is $3 more than $12 per hour.
The second day, the charge is $12 less than $15 per hour.
The difference in 0-hour charges is 3 -(-12) = 15. The difference in per-hour charges is 15 -12 = 3. The ratio of these is ...
$15/($3/h) = 5 h
The charges are the same after 5 hours.
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If you write equations for the charges, they will look like ...
y1 = 15 + 12(x -1)
y2 = 3 + 15(x -1)
Equating these charges, we have ...
15 +12(x -1) = 3 + 15(x -1)
12x +3 = 15x -12 . . . . . . . . eliminate parentheses
15 = 3x . . . . . . . . . . add 12-12x
x = 15/3 = 5 . . . . . . divide by 3
You might notice that the math here is very similar to that described in words, above.
The charges are the same after 5 hours.
Answer:
the first one is. hope helps
Answer:
9
Step-by-step explanation:
Adjacent AnglesTwo angles areAdjacent if they have a common side and a common vertex. ... VerticalAnglesVertical Angles are the anglesopposite each other when two lines cross.They are called "Vertical" because they share the same Vertex.Vertical Angles are Congruent/equivalent
Answer:
a) ∅ ∈ {∅} TRUE
b) ∅ ∈ {∅,{∅}} TRUE
c) {∅} ∈ {∅} FALSE
d) {∅} ∈ {{∅}} TRUE
e) {∅} ⊂ {∅,{∅}} TRUE
f ) {{∅}} ⊂ {∅,{∅}} TRUE
g) {{∅}} ⊂ {{∅},{∅}}FALSE
Step-by-step explanation:
To assess whether these statements are true or false, first observe the symbol:
"∈" means that element, as it is and as it is, belongs to the set. To belong to the set it must be within the symbols "{}"
On the other hand, the symbol "⊂" means "subset", that is, it is a subset that is included in the main set.
So:
c) is false because "{∅}" is not included in the set
g) is false because " {{∅}}" is not included in the set
