Answer:
Each magazine costs 3.90
Step-by-step explanation:
Take the total cost and divide by the number of magazines
46.80/12
3.90
Set the whole expression = to 0 and solve for x.
3x^(5/3) - 4x^(7/3) = 0. Factor out x^(5/3): x^(5/3) [3 - 4x^(2/3)] = 0
Then either x^(5/3) = 0, or 3 - 4x^(2/3) = 0.
In the latter case, 4x^(2/3) = 3.
To solve this: mult. both sides by x^(-2/3). Then we have
4x^(2/3)x^(-2/3) = 3x^(-2/3), or 4 = 3x^(-2/3). It'd be easier to work with this if we rewrote it as
4 3
--- = --------------------
1 x^(+2/3)
Then
4
--- = x^(-2/3). Then, x^(2/3) = (3/4), and x = (3/4)^(3/2). According to my 3 calculator, that comes out to x = 0.65 (approx.)
Check this result! subst. 0.65 for x in the given equation. Is the equation then true?
My method here was a bit roundabout, and longer than it should have been. Can you think of a more elegant (and shorter) solution?
Answer:
90 stamps
Step-by-step explanation:
We can solve this by writing an equation.
(38+26)+26
64+26
90
Therefore, they have 90 stamps altogether.
Answer:
y=x-3
Step-by-step explanation:
To find slope, use m=y2-y1/x2-x1, using values of x and y from two different points. Once you have found slope, take another point and use the point-slope equation y-y1=m(x-x1) and substitute in slope for m and the point for x1 and y1. Isolate y by subtracting y1 from both sides.