Answer:
<u>42 Hours.</u>
Step-by-step explanation:
As an equation where y is the total pages and x is hours of class:
y=1+1x since she started with 1 page and does 1 page per hour.
Setting the total pages she needs as 43 (y=43) we get:
43=1+1x
Subtract one on both sides
42=1x
The 1 doesn't need to be written so
x=42
Therefore, it'll take her 42 hours to write all those notes.
The perimeter of a rectangle is
2l + 2w
This has to be less than 30 because she has less than 30 inches of wood altogether.
The length must also be "no more than", which means less than or equal to, 12 inches.
Option A satisfies both of these conditions.
Answer:
(a) 
(b) 100
Step-by-step explanation:
Solving (a):
Given
Shape: Rectangle

Required
Calculate the perimeter.
Area is calculated as:

Where
and 
Substitute 64.8 for Area

Make L the subject:

Perimeter is calculated as:

Substitute 64.8/W for L


To solve further, we take the derivative of P and set it to 0, afterwards.

Set to 0

Collect Like Terms

Cross Multiply:

Divide through by 2

Take square roots


Recall that:

So:


The perimeter is:



Solving (b):
Given
((1 Group of 10 tenths) and (1 group of 8 tenths))/(6 groups of 3 tenths)
Required
Solve

So, the expression becomes:
((1 Group of
) and (1 group of
))/(6 groups of
)
This gives:
((1 Group of
) and (1 group of
))/(6 groups of
)
Group means product, so the expression becomes:

And, as used here means addition

Simplify:




you didn't give the options but constant of proportionality is a number you have to multiply x by to get y.
y=kx is the equation that expresses the proportionality of x and y
the constant of proportionality is k, so k=2
y= kx becomes y=2x
so y = 2x should be the answer