Answer:
y=0.2x+29
Step-by-step explanation:
Given that:
y is the total monthly of the A Fee and Fee plan.
x is the number of monthly minutes used.
- If a customer uses 290 minutes, the monthly cost will be $87, we have the pair (290, 87)
- If the customer uses 980 minutes, the monthly cost will be $225, this is the coordinate pair (980, 225).
We want to obtain an equation in the form: y=mx+b
First, let us determine the slope, m
Given points (290, 87) and (980, 225):
<u>Slope</u>
Next, we determine the y-intercept, b.
Substituting the pair (290, 87) and m=0.2 in y=mx+b, we obtain
87=0.2(290)+b
b=87-0.2(290)=29
Therefore, our equation in the form y=mx+b is:
y=0.2x+29
I believe the answer is 47.
X intercept = -1, y = 0 (-1, 0)
<span>y intercept = 2, x = 0 (0, 2)
</span>
slope between (-1, 0) and (0, 2):
slope = (2 -0)/(0 - -1) = 2/1 = 2, m = 2
Using point (-1, 0) x₁ = -1, y₁ = 0
y - y₁ = m(x - x₁)
y - 0 = 2*(x - -1)
y = 2(x + 1)
y = 2x + 2
<span>(3.5, 3) is the circumcenter of triangle ABC.
The circumcenter of a triangle is the intersection of the perpendicular bisectors of each side. All three of these perpendicular bisectors will intersect at the same point. So you have a nice self check to make sure your math is correct. Now let's calculate the equation for these bisectors.
Line segment AB:
Slope
(4-2)/(1-1) = 2/0 = infinity.
This line segment is perfectly vertical. So the bisector will be perfectly horizontal, and will pass through ((1+1)/2, (4+2)/2) = (2/2, 6/2) = (1,3).
So the equation for this perpendicular bisector is y = 3.
Line segment BC
(2-2)/(6-1) = 0/5 = 0
This line segment is perfectly horizontal. So the bisector will be perfectly vertical, and will pass through ((1+6)/2,(2+2)/2) = (7/2, 4/2) = (3.5, 2)
So the equation for this perpendicular bisector is x=3.5
So those two bisectors will intersect at point (3.5,3) which is the circumcenter of triangle ABC.
Now let's do a cross check to make sure that's correct.
Line segment AC
Slope = (4-2)/(1-6) = 2/-5 = -2/5
The perpendicular will have slope 5/2 = 2.5. So the equation is of the form
y = 2.5*x + b
And will pass through the point
((1+6)/2, (4+2)/2) = (7/2, 6/2) = (3.5, 3)
Plug in those coordinates and calculate b.
y = 2.5x + b
3 = 2.5*3.5 + b
3 = 8.75 + b
-5.75 = b
So the equation for the 3rd bisector is
y = 2.5x - 5.75
Now let's check if the intersection with this line against the other 2 works.
Determining intersection between bisector of AC and AB
y = 2.5x - 5.75
y = 3
3 = 2.5x - 5.75
8.75 = 2.5x
3.5 = x
And we get the correct value. Now to check AC and BC
y = 2.5x - 5.75
x = 3.5
y = 2.5*3.5 - 5.75
y = 8.75 - 5.75
y = 3
And we still get the correct intersection.</span>
The answer is that (It’s 6.6)
