Answer:
x=4, y=2
Step-by-step explanation:
2x - y = 6
x + y = 6
Add these together to eliminate y
2x - y = 6
x + y = 6
-----------------
3x = 12
Divide by 3
3x/3 = 12/3
x=4
But we still need y
x+y =6
4+y =6
Subtract 4 from each side
4+y-4 = 6-4
y=2
8 turnips + 6 turnips = 14 turnips together
8(14-9)+5
________
2
3. + 6
8(5)+5
______
9 + 6
40 + 5
————
15
45
____
15
= 3
Answer: B. The coordinates of the center are (-3,4), and the length of the radius is 10 units.
Step-by-step explanation:
The equation of a circle in the center-radius form is:
(1)
Where
are the coordinates of the center and
is the radius.
Now, we are given the equation of this circle as follows:
(2)
And we have to write it in the format of equation (1). So, let's begin by applying common factor 2 in the left side of the equation:
(3)
Rearranging the equation:
(4)
(5)
Now we have to complete the square in both parenthesis, in order to have a perfect square trinomial in the form of
:
<u>For the first parenthesis:</u>

We can rewrite this as:

Hence in this case
and
:

<u>For the second parenthesis:</u>

We can rewrite this as:

Hence in this case
and
:

Then, equation (5) is rewritten as follows:
(6)
<u>Note we are adding 9 and 16 in both sides of the equation in order to keep the equality.</u>
Rearranging:
(7)
At this point we have the circle equation in the center radius form 
Hence:



<em>Total number of coin that George has
16 + 28 + 32 + 4 = 80 coins
total number of coins sold by George
= 15% of 80
= 15/100 X 80
= 12 coins (ans)</em>