pinkrose1213
pinkrose1213 pinkrose1213
  • 16-06-2017
  • Mathematics
contestada

What is the 21st term of an arithmetic sequence with terms a6=50 and a11=85?

A. 125
B. 155
C. 185
D. 205

Respuesta :

mergl
mergl mergl
  • 16-06-2017
B.)155 

a1+d(n-1)
a1+d(6-1)=50
a1+5d=50
a1+d(11-1)=85
a1+10d=85
a1=50-5d
(50-5d)+10d=85
50-5d+10d=85
5d+50=85
5d=35
d=7
a1+7(6-1)=50
a1+35=50
a1=15
15+7(n-1)
15+7(21-1)
15+7(20)
15+140=155
Answer Link

Otras preguntas

What is a universalizing religion? a metaphysical religion that seeks inner peace through contact with extraterrestrial beings a religion that seeks to identify
Discuss the different social structures that characterized New England and the Chesapeake colonies during the first 100 years of their development.
What was one result of the gi bill
Which fossil evidence supports the idea of continental drift? Check all that apply. bacteria Glossopteris Lystrosaurus petrified wood Tyrannosaurus
Which statement best describes why computer models are useful in science? They can store and process data to make accurate weather predictions. They are used to
what’s number 3 & 4 ?!?!?!
Which of these is NOT associated with proteins? A. Amino acids B. Polysaccharide C. Enzymes D. Peptide bonds
Can you find the value of x
Please Help! Brainliest going!
77.7 repeating as a fraction