Answer:
First, let's define some variables.
x = # of cell phones sold.
y = total weekly income.
y = $5.25x + $80
a is the correct answer choice.
Step-by-step explanation:
Answer:
4x-12y=9
Step-by-step explanation:
y=1/3 x + 3/4
1/3 x-y=3/4
(x-3y)/3=3/4
4(x-3y)=3×3
4x-12y=9
Answer:
To figure out the common denominator for these fractions, I'll first need to factor that quadratic in the denominator on the right-hand side of the rational equation. This will also allow me to find the disallowed values for this equation. Factoring gives me:
x2 – 6x + 8 = (x – 4)(x – 2)
The factors of the quadratic on the right-hand side "just so happen" to be duplicates of the other denominators. This often happens in these exercises. (So often, in fact, that if you get completely different factors, you should probably go back and check your work.)
Step-by-step explanation:
The easiest way is to try the point (-4,1), that is, x=-4, y=1,
to see which equation works.
b works.
The usual way to do it is to find the equation of the circle
standard form of a circle is (x-h)²+(y-k)²=r², (h,k) are the coordinates of the center, r is the radius.
in this case, the center is (-2,1), so (x+2)²+(y-1)²=r²
the given point (-4,1) is for you to find r: (-4+2)²+(1-1)²=r², r=2
so the equation is (x+2)²+(y-1)²=2²
expand it: x²+4x+4+y²-2y+1=4
x²+y²+4x-2y+1=0, which is answer b.
