Since there is a $5 delivery charge, Valerie will surely spend those money.
Also, since a salad costs $7, and Valerie buys 3 of them, she will spend 21 more dollars.
So, salads and delivery charge sum up to 
This means that Valerie has 
dollars left. A drink costs $3, so she can buy
drinks.
The average rate of change formula is
f(b) - f(a)
arc = ----------------
b-a
Here, a= -10 and b = 10
(10)^2 + 9(10) + 18 - [ (-10)^2 + 9(-10) + 18]
Here arc = --------------------------------------------------------------
10 - (-10)
10^2 and -(-10)^2 cancel. 18 - 18 cancel.
90 - (-90) 180
This leaves us with arc = ----------------- = ------------- = 9 (answer)
20 20
No
if it has 1 acute angle, then the other 2 must be more than 90 each in other words, the other 2 angles must be over 180
all angles add to 180 no more
so no is answer
First you would subtract x from both sides to move all the x's to one side
Then you would add 4 to both side to move all the non x's to one side
Lastly divide by negative 15 to have x by itself
9/-15 =-.6
So x as has root at x=-0.6
14+38=52
52-38= 14
Answer: 38 and 14.
I think this is the answer.
