The closed formula for <span>an = an-1 – n will be found using the formula for arithmetic sequence given by:
an=a+d(n-1)
where
a=first term
d=common difference
n=number of terms
From the formula given:
a=4
d=n
thus the formula will be:
an=a+n(n-1)
an=4+n(n-1)
</span>
Are you factoring or simplifying?
2c-9=c
-9=-c
9=c
Hope that helps!
The answer is A, you can take 210 times .35 to get how much is taken off. Then you take 210 and subtract it by the answer you previously got
(X+12) + 140 = 180
X + 12 + 140 = 180
X + 152 = 180
X = 180 - 152
X = 28
