Answer:
The correct answer is <u>B. 15 units</u>
Step-by-step explanation:
the standard form for a horizontal ellipse is
X^2/a^2 + y^2/b^2 = 1
Substitute 54 for b and and use (8,18) as the
point to find a
x=8
y=18
8^2/a^2 + 18^2/54^2 =1
64/a^2 + 324/2916 = 1
324/2916 reduces to 1/9
64/a^2 + 1/9 = 1
64/a^2= 1-1/9
64/a^2 = 8/9
64*9/8 = a^2
576/8 = 72
A^2 = 72
A = square root(72) = 8.485
So formula
would be x^2/72 + y^2/2916 =1
ANSWER:
$9.0.
Each person will owe $9.0.
STEP-BY-STEP SOLUTION:
Total amount of people:
= 3
Total bill:
= $31.84
Discount off total bill:
= 15%
Total bill after discount:
= 31.84 × ( 100% - 15% )
= 31.84 × 85%
= 27.064
Total bill after discount split evenly / Amount each person will owe:
= 27.064 ÷ 3
= 9.0213 ( 3 repeater )
= $9.0 ( rounded to the nearest tenth )
12x - 8y = -12
6x + 4y = -30
Multiply the 2nd equation by 2, to make the Y coefficients opposite:
6x + 4y = -30 x 2 = 12x + 8y = -60
Now add the two equations:
12x -8y = -12 + 12x +8y = -60
= 24x = -72
Divide bothe sides by 24 to solve for x:
x = -72/24
x = -3
Now replace x with -3 in the first equation to solve for y:
12(-3) - 8y = -12
-36 - 8y = -12
Add 36 to each side:
-8y = 24
Divide both sides by -8 to solve for y:
y = 24 / -8
y = -3
X = -3 and y = -3
(-3,-3)
