1.
In any trapezoid, the length of the midsegment is

substituting the known values:



2.
Notice that since D and have the same y-coordinate, then DE is horizontal, and since F and D have the same x-coordinate, FD is vertical.
Thus FD and DE are perpendicular, so the triangle FED is a right triangle.
The median drawn from the right angle, is equal to half the hypotenuse.
That is, |DO|=1/2 |FE|, thus |OE|=|OF|=|OD|, are all radii of the circle centered at O.
O is the midpoint of EF, and is found by the Midpoint formula:

Answer:
1. 14
2. (4, 3)
The inequality you require is
The number of bottles left at the end of each day is 48 - 3x. So it is:-
48 - 3x < 10
Solving the inequality to find the last part of question:-
-3x < 10 - 48
-3x < -38
x > 38/3 = 12 2/3
So answer is 13 days.
The answer is 0.02
All you have to do is divide 1 by 50. You can think of it as if it was divided by 100. If you multiply the numerator and denominator by 2 you get 2/100 which is 0.02
Let x = the unknown number
five more than a number = twice the number
x + 5 = 2x
5 = 2x - x
5 = x
( Balance method is used to solve )
substitution
x + 5 = 2x
5 + 5 = 2 x 5
10 = 10
answer : the unknown number is 5
Since the gas it is getting compressed with a change on temperature, we consider that the pressure is constant, and of course the number of mole is constant (same gas), therefore, from the ideal gas law
P
V
=
n
R
T
we can say:
V
T
=
constant
Therefore,
V
1
T
1
=
V
2
T
2
⇒
T
1
=
V
1
×
T
2
V
2
⇒
T
1
=
12
L
×
300
K
8
L
=
450
K
A=450k