Answer:
x = 1, y = 10
Step-by-step explanation:
y = -5x + 15 --- Equation 1
2x + y = 12 --- Equation 2
Substitute y = -5x + 15 into Equation 2:
2x + y = 12
2x - 5x + 15 = 12
Evaluate like terms.
15 - 3x = 12
Isolate -3x.
-3x = 12 - 15
Evaluate like terms.
-3x = -3
Find x.
x = -3 ÷ -3
x = 1
Substitute x = 1 into Equation 2:
2x + y = 12
2(1) + y = 12
2 + y = 12
Isolate y.
y = 12 - 2
y = 10
That's very interesting. I had never thought about it before.
Let's look through all of the ten possible digits in that place,
and see what we can tell:
-- 0:
A number greater than 10 with a 0 in the units place is a multiple of
either 5 or 10, so it's not a prime number.
-- 1:
A number greater than 10 with a 1 in the units place could be
a prime (11, 31 etc.) but it doesn't have to be (21, 51).
-- 2:
A number greater than 10 with a 2 in the units place has 2 as a factor
(it's an even number), so it's not a prime number.
-- 3:
A number greater than 10 with a 3 in the units place could be
a prime (13, 23 etc.) but it doesn't have to be (33, 63) .
-- 4:
A number greater than 10 with a 4 in the units place is an even
number, and has 2 as a factor, so it's not a prime number.
-- 5:
A number greater than 10 with a 5 in the units place is a multiple
of either 5 or 10, so it's not a prime number.
-- 6:
A number greater than 10 with a 6 in the units place is an even
number, and has 2 as a factor, so it's not a prime number.
-- 7:
A number greater than 10 with a 7 in the units place could be
a prime (17, 37 etc.) but it doesn't have to be (27, 57) .
-- 8:
A number greater than 10 with a 8 in the units place is an even
number, and has 2 as a factor, so it's not a prime number.
-- 9:
A number greater than 10 with a 9 in the units place could be
a prime (19, 29 etc.) but it doesn't have to be (39, 69) .
So a number greater than 10 that IS a prime number COULD have
any of the digits 1, 3, 7, or 9 in its units place.
It CAN't have a 0, 2, 4, 5, 6, or 8 .
The only choice that includes all of the possibilities is 'A' .
5.1 • 0.79 = 4.029
the apples cost $4.03
Answer:
It seems the question is incomplete as the two data sets implied from the question are not visible.
However, two data sets having identical measures of center have a difference.
Step-by-step explanation:
Let's consider these two data sets:
2, 2, 3, 5, 6, 6 and 1, 1, 1, 1, 1, 19
Both were contrived.
The most reliable among the measures of center is the mean. The mean of each is calculated by summing the data and dividing by the number of elements. In both sets, the mean is 4.
The data in the first set seem to be concentrated around the mean indeed. But for the second data set, one of them, 19, is obviously very far from the others and the mean. We need another measure to describe this: standard deviation.
Its formula is:
represents each data, 
is the mean and 
is the number of items. 
is the deviation from the mean of each data item.
For the first data set, 
For the second data set,
The low value of 
for the first set indicates that the items are all closer to the mean than for the second set.
Variance is the square of the standard deviation. It could also be used.
Answer:
∑ (n = 1 to 5) (2·(-4)^(n - 1))
S5 = 2·((-4)^5 - 1)/((-4) - 1) = 410
