This sequence starts with an initial set; let’s call it s1. This set contains 20 cans, and every set following would have two less cans than the last set. So,
s1=20
s2=s1-2=18
s3=s2-2=16
•
•
•
s9=s8-2=4
How many cans in the display represents the value of each set added together, so we can denote this as
s1+s2+s3+...+s9
and replacing with values:
20+18+16+...+4 = 108
The number of cans in the display equals 108.
(The set notation seems weird, but by practicing this application now, the Calculus version will seem easier.)
Answer:
54 I think
Step-by-step explanation:
I just did 15 divided by 9 and got 5/3 and then did 90 divided by 5/3 and got 54
2x-3y=7
-3y = -2x+7
y= 2x/3-7/3
slope of 2/3 (rise 2, run 3)
y-intercept of -7/3
Would be a positive line, starting low on left and rising towards right
Answer: A
(He has the side lengths in the wrong place in the cosine ratio)
$21.45 x 6 = $128.7
$128.7 + $10.60 = $139.3
Charlie will have saved $139.3 in 7 months
