Given that we have the change in temperature over 7 hours and we are looking for the change over 1 hour, we can divide the total change in temperature by 7. Thus, the change in temperature would be 
.
Additionally, this can be solved by equations:
By using two different methods, we can determine that the change each hour was equal to 42/7 C° per hour.
Answer:
The third one, y = 5 x 10
Step-by-step explanation:
y = number of Kate's pens, 5 = how many times more pens Kate has than Mark, and 10 = how many pens Mark has.
Answer:
Cost of bolts = x = $0.3
Cost of washers = y = $0.167
Step-by-step explanation:
Let us represent:
Cost of bolts = x
Cost of washers = y
Luke buys 4 bolts and 6 washers for $2.20
Hence:
4x + 6y = 2.20....Equation 1
Holly spends $1.80 on 3 bolts and 5 washers at the same local hardware store.
3x + 5y = 1.80....Equation 2
Combining both Equations
4x + 6y = 2.20....Equation 1
3x + 5y = 1.80....Equation 2
Multiply Equation 1 by 3 and Equation 2 by 4 to eliminate x
12x + 18x = 6.6.....Equation 4
12x + 20x = 7.2.......Equation 5
Substract Equation 4 from 5
= 2x = 0.6
x = 0.6/2
x = $0.3
Solving for y
4x + 6y = 2.20....Equation 1
4 × 0.3 + 6y = 2.2
1.2 + 6y = 2.2
6y = 2.2 - 1.2
6y = 1.0
y = 1.0/6
y = $0.167
Cost of bolts = x = $0.3
Cost of washers = y = $0.167
Answer: Option A
Step-by-step explanation:
Note that for the initial year, 1990, the population was 5.3 billion.
The exchange rate is 0.09125 billion per year. In other words, each year there are 0.09125 billion more people.
In year 2 there will be 0.09125 * 2 billion people
In year 3 there will be 0.09125 * 3 billion people
In year 4 there will be 0.09125 * 4 billion people
In year t there will be 0.09125 * t billion of people
So the equation that models the number of people that there will be as a function of time is:
Where 
is the initial population
billion
r is the rate of increase
billion per year
finally the equation is:
The correct answer is option A.
Option c is right that is x>-2 because point is open.
