I’m pretty sure they are multiplied, if I understand your wording
When you add something, you gain more of it. Therefore, it should be positive 2
2
Answer:
10 rows with 6 passengers per row
Step-by-step explanation:
Let x be the number of rows and y the number of passengers per row.
Then we can interpret the story as the following two equations:
xy=60
(x+2)(y-1)=60
Solving these two equations:
y=60/x
(x+2)(60/x-1)=60 (substitute y)
60 - x + 120/x - 2 = 60 (multiply by -x)
x² + 2x - 120 = 0 (factor)
(x-10)(x+12) = 0
x = 10
y = 60/10 = 6
and indeed 10 * 6 = 60 and also 12 * 5 = 60
The denominator of the second fraction is the difference of squares, so can be factored using the formula for that.
(n^2 -4) = (n -2)(n +2)
Now, you will note that the second fraction has a numerator that is equal to one of the factors in the denominator. In other words, the whole fraction can be simplified to ...
(n +2)/((n +2)(n -2)) = 1/(n -2) . . . . with the restriction n≠-2
This reduced form of the fraction has the same denominator as the first fraction, so you can say that the lowest common denominator is that: (n -2).
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If there is some reason you don't want to reduce the second fraction, the lowest common denominator will be (n -2)(n +2).