Answer:

Step-by-step explanation:
Based off of what we do know, if we can find length DB we can use the pythagorous theorem (I will be assigning the variable z)

First equation is for triangle ABD
Second is for BCD
And the last one is for ACD
Substitute
and 

As discovered before

Answer:
Step-by-step explanation:
Let m = the amount books Rachel sold on Monday.
then t = the amount books Rachel sold on Tuesday.<span>
then w = </span><span>the amount books Rachel sold on Wednesday.
On Tuesday she sold twice as she did on Monday.
t = m * 2
On Wednesday she sold 6 fewer books than she did on Tuesday
w = t - 6
Now for the fun.
t = m * 2
w = t - 6
Substitute t for real value
w = m * 2 - 6
Now solve for m.
w - 6 = m * 2 <-- Transpose the 6
(w-6)/2 = m <-- Transpose the 2.
m = (w-2)/2 < The Law of Reflexive Property of Equality</span>
By the fundamental theorem of calculus,

So we have


