- I’m assuming the expression implies the following:
(1-n)/(n^2 - 1)
The steps goes as follows:
= -(n-1)/(n^2-1) (factored a negative out)
= -(n-1)/[(n+1)(n-1)] (Factored denominator into a difference of squares, but don’t just blindly accept the fact, expand it and you should get the original denominator)
At this point, the (n-1) terms cancel, as you should know: a real number, besides 0, over itself is 1.
= -1/(n+1) , which is the answer
Note: You could also see it as 1/-(n+1) or 1/(-n-1)
#1 is A because the equation is pi x diameter which would be 18.84
7.86 / 6 = 1.31 per unit
8.88 / 8 = 1.11 per unit
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So we know 48 are scored collectively between the two teams, let’s call team 3 “x” and let’s call 4 “y” just so it’s easier to visualise:
We are told that x+y=48
And also told y=3x
If we substitute that in we get
X+3x=48
Collect like terms to get
4x=48 then divide by 4 to get
X=12
We now know that team 3 scored 12 goals
And if team 4 scored 3 times as many we can do 3*12=36 so team 4 scored 36
To make sure it’s correct 36+12=48
Hope this helped :)