You can formulate your own equations by analyzing the given problem and its statements. You can do some illustrations so you can understand it better. Introduce some variables and the rest is algebra. For example:
An orange costs $2 while a banana costs $1.5. How many oranges and bananas do you have to buy such that the total cost would equal to $20. You bought a total of 12 fruits.
First, you have to introduce variables. Let 'x' be the number of oranges and 'y' be the number of bananas. One equation you can get from here is knowing the amount of total cost: 2x + 1.5y = 20. Then, the other equation would be knowing the amount of fruits: x+y=12. You have two unknowns and two equations. Hence, you can solve the problem. Solving them simultaneously, you would get that x=4 and y=8.
Louise wants to factorize completely the given polynomial 
Grouping first, second terms together and third, fourth terms together
= 
Taking
common from first and second terms of the given expression and taking 5 common from the third and fourth terms.
=
Taking (x+3) common from the given expression,
=
is the completely factored form.
C. 48 inches
Add all the sides to find the perimeter
<span>idk why they want the dratted "k" . it is so simple w/o it !
in the form y = ab^x, a = 4000, b = 4400/4000 = 1.1, x = t/2
N = 4000*1.1^(13/2) = 7432 <------
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now you won't be satisfied with simplicity, so
4400 = 4000e^2k
e^2k = 1.1
k = ln 1.1/2 = .0477 to 4 dp
N(13) = 4000e^(13*.0477) = 7436 <------
note that apart from a roundabout way, you get a less accurate ans !</span>
We need a picture of the graph