Notice that
13 - 9 = 4
17 - 13 = 4
so it's likely that each pair of consecutive terms in the sum differ by 4. This means the last term, 149, is equal to 9 plus some multiple of 4 :
149 = 9 + 4k
140 = 4k
k = 140/4
k = 35
This tells you there are 35 + 1 = 36 terms in the sum (since the first term is 9 plus 0 times 4, and the last term is 9 plus 35 times 4). Among the given options, only the first choice contains the same amount of terms.
Put another way, we have
but if we make the sum start at k = 1, we need to replace every instance of k with k - 1, and accordingly adjust the upper limit in the sum.
The answer is 6 because 21+9=30 and 30-6=24 and 24 is the number of students in the class.
For the first one, to find the missing fraction, add the first two fractions and subtract that from the last fraction. For the second question, subtract the first two fractions then add that to the last fraction. Hope this helps.
Answer:
Width: 10 inches
Length: 15 inches
Step-by-step explanation:
Let the width be w.
Since the length is 5 inches longer than its width, the length = w +5.
Area of rectangle = length x width
w (w +5) = 150
w^2 + 5w = 150
w^2 + 5w -150 = 0
Using quadratic formula,
w = 10 or -15
Since the width cannot be negative,
the width is 10 inches.
Now just substitute w=10 into length = w +5.
length = 10 + 5
= 15 inches
Not sure
te rate is r
for decay, it is
A=P(1-r)^t
r=rate
P=present amount
dunno what b is
but I guess
A=28000(1-0.13)^t
A=28000(0.87)^t
I would guess the decay factor would be 0.87
