Sum = n/2[2a + (n - 1)d] where a = first term, n = number of terms and d = common difference
(a) 30/2(2 x 5 + (30 - 1) x d) = 1455
10 + 29d = 1455 / 15
29d = 97 - 10
d = 87 / 29 = 3
(b) 7/2(2 x 9 + (7 - 1)d) = 0
18 + 6d = 0
6d = -18
d = -3
Answer:
<em>Peter now has 54 baseball cards</em>
Step-by-step explanation:
<u>Percentages</u>
Assume Peter had x baseball cards in his collection. The 35% of his initial collection is
35 * x / 100= 0.35x
We know that those 14 new baseball cards represent a 35% of his previous collection, therefore we can set a simple equation
0.35x=14
When we solve for x, we'll know how many baseball cards Peter had before
x=14 / 0.35 = 40
Peter had 40 cards, he added 14 new baseball cards, so he now has 40+14=54
Peter now has 54 baseball cards
Step-by-step explanation:
anything greater than 195.
Log x+ log 7= log 42
log x=log 42 - log 7
log x=log 42/7 [ log a - log b= log (a/b) ]
log x= log 6
therefore:
x=6
Answer: x=6
