They own a total of 120 CDs.
GIVEN:
Ella: ratio of rock music to total CDs that she owns 25/40
Paolo: has 50 rock music CDs. The ratio of rock music to total CD is equal to Ella's ratio.
Proportion: a/b = c/d where ad = bc
25/40 = 50/x
25x = 40 * 50
25x = 2000
25x / 25 = 2000 / 25
x = 80 total of Paolo's CDs
Total of Ella's CDs = 40
Total of Paolo's CDs =<u> 80</u>
Total CDs in all 120
Answer:
<u><em>Answer is below</em></u>
Step-by-step explanation:
<u><em>13x+1+7x+19</em></u>
<u><em>Combine Like Terms:</em></u>
<u><em>=13x+1+7x+19</em></u>
<u><em>=(13x+7x)+(1+19)</em></u>
<u><em>=20x+20</em></u>
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>
