U2 =15, U4=135, U5= ?, S3=? tolong dibantu :)
Matematika
pemula93
Pertanyaan
U2 =15, U4=135, U5= ?, S3=?
tolong dibantu :)
tolong dibantu :)
1 Jawaban
-
1. Jawaban salsa2000
u2= a+b = 15
u4= a+3b = 135
________ -
-2b= -120
b= 60
Substitusi b=60
a+b =15
a+60=15
a = -45
Maka
U5= a+4b
= -45+4(60)
= -45+240
= 195
Maka s3= n/2(2a+(n-1)b)
= 3/2(2(-45)+2(60))
= 3/2(-90+120)
= 3/2(30)
= 45