A. $14.99 .. do $49.98/2 = $24.99 and then subtract $10.
B. $19.99 .. do $49.98-19 = $39.98 and then divide it by 2.
A word to the wise: It's <span> f(x)=125(0.9)^x, where ^ represents exponentiation.
In this case the ave. value over the interval [11, 15] is
125(0.9)^15 - 125(0.9)^11
------------------------------------- = (125/4) [ 0.9^15 - 0.9^11)
15 - 11 = (31.25) [ 0.2059 - 0.3138 ] = a negative result
= (31.25)(-0.1079) = -3.372 (av. r. of c.
over the interval [11,15] )
Do the same thing for the time interval [1,5]. Then compare the two rates of change.</span>
Use BODMAS or BIDMAS (Brackets, over Indices, Division, Multiplication, Addition, the Subtraction, this tells you which order to do things in)
As you cant do √10 in the brackets you do the indices, so (√10)³
Split this up to make it easier
(√10)³= √10 x √10 x √10 = 10√10
You the multiply this by 9
9 x 10√10 = 90√10
then multiply by 5
5 x 90√10 = 450√10 = 1423.024947 (using calculator)
<span>1. Find the difference
2. Divide the difference by the original number it went up from.
</span>
450-375 = 75
75/375 = 0.2
You got a 20% raise.
Proof:
375*.2 = 75
375+75 = 450