Answer:
<em>C. 15</em>
Step-by-step explanation:
Assuming that these segments formed from each parallel line are proportional, x/5 = x-6/3.
Now cross multiply by multiplying each denominator by the opposite numerator, this is so the denominators or bottom numbers of each fraction will cancel.
x/5 = x–6/3 → (3)(x/5) = (3)(x–6/3) → 3x/5 = x–6 →
(5)(3x/5) = (5)(x–6) → 3x = 5(x–6) → 3x = 5x – 30.
The last step is to do the basic algebra to find x:
3x = 5x – 30
–5x –5x
[5x will cancel when you subtract both sides by 5x]
-2x = -30
(-1) (-1)
[2 negatives make a positive when -1 is multiplied by an expression with a negative coefficient]
2x = 30
÷2 ÷2
[divide both sides by 2 to simplify 2x to x]
x = 15
_____
You can also check that both sides are proportional because
5 → x
x = 15
5 → 15
3 → x – 6
x = 15
3 → 9
5 × <u>3</u> = 15
3 × <u>3</u> = 9
Answer:
16 lawns
Step-by-step explanation:
set up a proportion:
(4/5 ÷ 1) = (x÷20)
cross-multiply:
5x = 80
x = 16
well, we can say that 1 hour is 100%, what is 2/5 hr off of it in percentage?
A) zeroes
P(n) = -250 n^2 + 2500n - 5250
Extract common factor:
P(n)= -250 (n^2 - 10n + 21)
Factor (find two numbers that sum -10 and its product is 21)
P(n) = -250(n - 3)(n - 7)
Zeroes ==> n - 3 = 0 or n -7 = 0
Then n = 3 and n = 7 are the zeros.
They rerpesent that if the promoter sells tickets at 3 or 7 dollars the profit is zero.
B) Maximum profit
Completion of squares
n^2 - 10n + 21 = n^2 - 10n + 25 - 4 = (n^2 - 10n+ 25) - 4 = (n - 5)^2 - 4
P(n) = - 250[(n-5)^2 -4] = -250(n-5)^2 + 1000
Maximum ==> - 250 (n - 5)^2 = 0 ==> n = 5 and P(5) = 1000
Maximum profit =1000 at n = 5
C) Axis of symmetry
Vertex = (h,k) when the equation is in the form A(n-h)^2 + k
Comparing A(n-h)^2 + k with - 250(n - 5)^2 + 1000
Vertex = (5, 1000) and the symmetry axis is n = 5.
