Question #59ec4

2 Answers
Apr 8, 2017

Answer:

See the entire solution process below:

Explanation:

The sequence takes the difference between the two previous numbers, doubles it, and adds this to the last number in the sequence:

Looking at the first two terms in the sequence:

#9 - 4 = 5#; #5 xx 2 = 10#, add it to the last number, #9 + 10 = 19#

Now, look at #9# and #19#:

#19 - 9 = 10#; #10 xx 2 = 20#, add it to the last number, #19 + 20 = 39#

Now, look at #19# and #39#:

#39 - 19 = 20#; #20 xx 2 = 40#, add it to the last number, #39 + 40 = 79#

The missing term in the sequence is: #color(red)(39)#

Apr 8, 2017

Answer:

#39#

Explanation:

Apparently the differnce between term doubles every time:

#4+5=9#

#9+10=19#

#19+20=39#

#39+40=79#

The next term will be:

#79+80=159#