Seems to be an arythmetic sequence
Sn=[n(a1+an)]/2
where
Sn means sum of all terms up the nth term
n=number of terms
a1=first term
an=nth term
so from 86 to the 22th term is from a1 to a22
find teh sequence
miknus 7 each time
an=a1+d(n-1)
an=87-7(n-1)
find 22n term
a22=87-7(22-1)
a22=87-7(21)
a22=87-147
a22=-60
S22=[22(87-60)]/2
S22=[22(27)]/2
S22=594/2
S22=297
the sum is 297
We can use the Front Outside Inside Last (FOIL) method to expand the double bracket
Front ⇒
Outside ⇒
Inside ⇒
Last ⇒
Put the four terms together we have
, then collect like terms
$9 represents the Mode
Mode is data that occurs the most
First evaluate 990 x 37.
990 x 37 = 36630
Test the given numbers to find the pair that adds up to 36630.
Test 297.
The missing pair will be
36630 - 297 = 36333
Will not work
Test 693.
36630 - 693 = 35937
Will not work
Test 2970.
36630 - 2970 = 33660
Will not work
Test 6930
36630 - 6930 = 29700
This works, because 6930 + 29700 = 36630.
Answer: 6930 and 29700.
