Page 29 - DIGITAL BOOK MUHAMMAD AZWARDI NASUTION
P. 29
CONTOH 7 :
Three number form arithmetic sequence. The
sum of its = 21 and the multiplication of its
=168.Find the three number.
Answer:
Suppose that the three number are
a - b ,a, a + b
3a=21 then a=7
(a-b) a (a + b) = 168
(7-b)7(7+b)=168
49-b = 24 then b2=25
2
b = -5 or b=5
For b=-5
The three number are: 12,7,2
Meinwhile for b=5
The three number are: 2,7, 12
