Answer:
-6
Step-by-step explanation:
3n = n² - 54
n² - 3n - 54 = 0
n² - 9n + 6n - 54 = 0
n(n - 9) + 6(n - 9) = 0
(n - 9)(n + 6) = 0
n = 9 , -6
I believe its C
Hoped I help :)
And have a nice day/weekend :)
<span />
Answer:
x = 5/39
, y = 539/39
Step-by-step explanation:
Solve the following system:
{y - 2.5 x = 13.5
12.25 x - y = -12.25
In the first equation, look to solve for y:
{y - 2.5 x = 13.5
12.25 x - y = -12.25
y - 2.5 x = y - (5 x)/2 and 13.5 = 27/2:
y - (5 x)/2 = 27/2
Add (5 x)/2 to both sides:
{y = 1/2 (5 x + 27)
12.25 x - y = -12.25
Substitute y = 1/2 (5 x + 27) into the second equation:
{y = 1/2 (5 x + 27)
1/2 (-5 x - 27) + 12.25 x = -12.25
(-5 x - 27)/2 + 12.25 x = 12.25 x + (-(5 x)/2 - 27/2) = 9.75 x - 27/2:
{y = 1/2 (5 x + 27)
9.75 x - 27/2 = -12.25
In the second equation, look to solve for x:
{y = 1/2 (5 x + 27)
9.75 x - 27/2 = -12.25
9.75 x - 27/2 = (39 x)/4 - 27/2 and -12.25 = -49/4:
(39 x)/4 - 27/2 = -49/4
Add 27/2 to both sides:
{y = 1/2 (5 x + 27)
(39 x)/4 = 5/4
Multiply both sides by 4/39:
{y = 1/2 (5 x + 27)
x = 5/39
Substitute x = 5/39 into the first equation:
{y = 539/39
x = 5/39
Collect results in alphabetical order:
Answer: {x = 5/39
, y = 539/39
