Answer:
n = 6 + 
or n = 6 -
Step-by-step explanation:
We can solve this equation using the quadratic formula OR Completing the Square method.
n² + 14 = 12n
rearrange : n² - 12n + 14 = 0
here a= 1 , b = -12, c = 14
the quadratic formula says: x = - b/ (2a) + root(b^2 - 4ac) / (2a)
or x = - b/ (2a) - root(b^2 - 4ac) / (2a)
x = - (-12)/ (2) + root((-12)^2 - 4*14) / (2)
x = 6 + root (144 - 56) / 2
x = 6 + root(88)/2
x = 6 + root(4*22) / 2
x = 6 + 2*root(22)/2
x = 6 + root(22) = 6 +
so x =6 + or x = 6 -
In this case x = n
n = 6 + or n = 6 -
Answer:
540
Step-by-step explanation:
Amount of antifreeze in the 90% solution + amount of antifreeze in the 20% solution = amount of antifreeze in the 80% solution
0.90 x + 0.20 (90) = 0.80 (x + 90)
0.90 x + 18 = 0.80 x + 72
0.10 x = 54
x = 540
You need 540 gallons of 90% antifreeze solution.
Answer:
6kg pure copper and 30 kg 10% copper was mixed to give 36kg of 25% alloy
Step-by-step explanation:
Here, we want to produce 36 kg of 25% alloy
Let the Pure copper be x kg while 10% alloy be y kg
Pure copper is simply 100% copper
Thus;
x + y = 36 •••••(i)
Then;
100% of x + 10% of y = 25% of 36
= x + 0.1y = 9 •••••• ii)
From i x = 36-y
from ii, x = 9-0.1y
Equate both x
36-y = 9-0.1y
36-9 = 0.1y + y
0.9y = 27
y = 27/0.9
y = 30
x = 36-y
x = 36-30
x = 6 kg
We can represent the cost of the notebooks with by saying 0.75n, and the cost of the pens by saying 0.55p.
0.75n+0.55p will be the total cost before tax. Now, we need to add on tax. Tax will be 0.0625 times the total amount, so we can represent the cost by saying
(0.75n+0.55p) + 0.0625(0.75n+0.55p), so the answer is B.
Answer:
P.ut your age since you're the bus driver
Step-by-step explanation:
Hope this helps!
