5 x 6 + 7? Is that what the answer is, I didn't get the question towards the end. :)
Answer:
C
Step-by-step explanation:
As you know, 390% is 3.9. You multiply 3.9*30 and get 117 or something. That rounds to about 120, so C.
I hoped that helped
Answer: A. A=(1000-2w)*w B. 250 feet
C. 125 000 square feet
Step-by-step explanation:
The area of rectangular is A=l*w (1)
From another hand the length of the fence is 2*w+l=1000 (2)
L is not multiplied by 2, because the opposite side of the l is the barn,- we don't need in fence on that side.
Express l from (2):
l=1000-2w
Substitude l in (1) by 1000-2w
A=(1000-2w)*w (3) ( Part A. is done !)
Part B.
To find the width w (Wmax) that corresponds to max of area A we have to dind the roots of equation (1000-2w)w=0 ( we get it from (3))
w1=0 1000-2*w2=0
w2=500
Wmax= (w1+w2)/2=(0+500)/2=250 feet
The width that maximize area A is Wmax=250 feet
Part C. Using (3) and the value of Wmax=250 we can write the following:
A(Wmax)=250*(1000-2*250)=250*500=125 000 square feets
1. 3y
multiplying 3 and y together gets 3y
2. y-5
5 less implies that we subtract 5 from y
3. y+7
adding 7 to y, self-explanatory
4. 9y
same thing as #1
5. 
quotient of implies division, since number y is listed first, y is the numerator
The error bars are used to indicate the variability of the data presented in a graph.
There are several quantities that can be used to generate error bars in the graph. These are:
standard deviation
standard error
confidence interval
Usually, one standard deviation above and below the mean is used although it is advised to indicate which variability data is used to generate the error bars in the graph since the 3 quantity given are not equal.