Step-by-step explanation:
8x+3y=18
subject y according y=mx+c
y=8/3x-6
(-9,-13)
substitute -9 to y=8/3x-6
-13=8/3×(-9)+c
11=c
y=8/3x+11
Answer:
Una relación lineal es de la forma:
y = a*x + b.
donde a es la pendiente y b es la ordenada al origen.
en este caso, y es el precio de la camioneta, x es el numero de años que pasaron, a es la razon de depreciación de la camioneta y b es el precio inicial de la camioneta, b = $42,000.
Sabemos que después de 5 años, el precio de la camioneta es 21,000, entonces podemos resolver:
$21,000 = a*5 + $42,000
a*5 = $21,000 - $42,000 = -$21,000
a = -$21,000/5 = -$4,200
Esto significa que el precio decae $4,200 por año
Answer:
(1/2)s = 345
s = 690 (Maggie's savings balance)
Step-by-step explanation:
For any problem, word problem or otherwise, you start be reading and understanding the problem. You should specifically look for
- what you're being asked to find (what is the question to answer)
- the information you're given that is relevant to the question asked.
Here, you're asked to find a savings account balance. You're told that $345 is half that amount.
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After you decide what you're looking for and the given relevant information, you use the problem statement and your personal knowledge to write one or more equations relating what you know to what you want to find.
A first step for doing this is to define any necessary variables. In this problem, we can use "s" for the original savings balance (in dollars). (I like to choose letters that remind me what they stand for. "x" or "y" can sometimes get mixed up. For a one-variable problem, it doesn't really matter what you call it. It is helpful to be clear about the units of measure of any variables. Confusion there can also lead to errors.)
The problem statement tells us that half the savings account amount is $345, so our equation is ...
(1/2)s = 345
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The "one step" required to solve this so to multiply both sides of the equation by 2.
s = 690
Maggie had $690 in her savings account before she bought the computer.
The quadratic formula is expressed as:
x = (-b +/- √(b^2 - 4ac) ) / 2a
where a, b and c are the coefficients of the quadratic equation with the form ax^2 + bx + c=0
Therefore, the quadratic equation would be:
a = 3
b = -6
c = 8
x = (-(-6) +/- √((-6)^2 - 4(3)(8) ) / 2(3)
Hope this helps.
