Answer:
(2, 7) is the correct ordered pair.
Step-by-step explanation:
5x + 3y = 31
2x + 3y = 25 Subtract to eliminate the y variable:
3x = 6
x = 6/3
x = 2.
Substitute x = 2 in the first equation:
5*2 + 3y = 31
3y = 31-10 = 21
y = 21/3
y = 7.
Check the result by substituting for x and y in the second equation:
2(2) + 3(7) = 25
4 + 21 = 25
25 = 25.
Answer:
y=0.2x+29
Step-by-step explanation:
Given that:
y is the total monthly of the A Fee and Fee plan.
x is the number of monthly minutes used.
- If a customer uses 290 minutes, the monthly cost will be $87, we have the pair (290, 87)
- If the customer uses 980 minutes, the monthly cost will be $225, this is the coordinate pair (980, 225).
We want to obtain an equation in the form: y=mx+b
First, let us determine the slope, m
Given points (290, 87) and (980, 225):
<u>Slope</u>

Next, we determine the y-intercept, b.
Substituting the pair (290, 87) and m=0.2 in y=mx+b, we obtain
87=0.2(290)+b
b=87-0.2(290)=29
Therefore, our equation in the form y=mx+b is:
y=0.2x+29
Answer:
The function that represents the mass of the sample after t days is
.
The percentage rate of change per hour is of -2.46%.
Step-by-step explanation:
Exponential amount of decay:
The exponential amount of decay for an amount of a substance after t days is given by:

In which A(0) is the initial amount, and r is the decay rate, as a decimal.
Element X is a radioactive isotope such that its mass decreases by 59% every day. The experiments starts out with 390 grams of Element X.
This means, respectively, that 
So



The function that represents the mass of the sample after t days is
.
Hourly rate of change:
Decreases by 59% every day, which means that for 24 hours, the rate of change is of -59%. So
-59%/24 = -2.46%
The percentage rate of change per hour is of -2.46%.
The numbered cubes might be referring the dice. We know that there are 36 ways of dice will occur.
Take the unique list of the following pair for which the sum is less than 6, and these are
(1,1) (1,2) (1,3) (1,4) (2,1) (2,2) (2,3) (3,1) (3,2) (4,1)
Therefore there are 10 possible ways we could get.
In probability, it is a ratio of the successful outcomes over the total number of possible outcomes.
P = 10/36 = 5/18