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
Answer: -1/2 and 1/3
Step-by-step explanation:
Answer:
9ab+3a
Step-by-step explanation:
2a*3b=6ab
2a*1=2a
a*3b=3ab
a*1=a
adding everything together=6ab+2a+3ab+a=9ab+3a