Well, this problem is best solved by setting up a system of two linear equations.
A linear equation can be defined
y=mx+b
where
b=initial value (when x=0), and
m=rate of increase or decrease.
In the given example, the x-axis represents hour, and the y-axis, number of cells.
Chemical #1
initial value = b = 12000 cells
rate = m = -4000 / hr
The equation is therefore
y1=-4000x+12000......................(1)
Similarly, for chemical #2
initial value = b = 6000 cells
rate = m = -3000 / hr
The equation is therefore
y2=-3000x+6000 .......................(2)
The time the two will have an equal sized colony would represent the solution of the system of equations (1) and (2), i.e. when y1=y2
which means
-4000x+12000 = -3000x+6000
transpose and solve for x
4000x-3000x = 12000-6000
1000x=6000
x=6 hours.
At 6 hours from the start,
y=-4000x+12000 = -4000*6+12000 = -24000+12000 = -12000 cells
So the solution is x=6, y=-12000, or (6,-12000)
Physical interpretation
Since cells cannot have a negative number, the two are actually equal before six hours, when they are both zero.
Case 1: y=0 when x=3
Case 2: y=0 when x=2
Therefore, after three hours, both trials will have zero cells.
You have to judge whether to give the mathematical solution (x=6,y=-12000) or the physical interpretation (x=3, y=0) as the answer.
Answer: 6 full plots I believe
Step-by-step explanation:
Length of the diameter = sqrt ( (-12- (-8)^2) +(2-0)^2) )
= sqrt (16 + 4) = sqrt20
so radius = sqrt 20 / 2 = sqrt5
so r^2 = 5
Center of the circle = coordinates of the midpoint of the diameter =
-8-12/2 , 2-0 / 2 = (-10, 1)
(x - a)^2 + (y - b)^2 = r^2 is general form of a circle so here the circle is:_
(x + 10)^2 + (y - 1)^2 = 5 Answer
Its B
Answer:
x^2+x+1
Step-by-step explanation:
(3x^2+4x−1)+(−2x^2−3x+2)
Combine like terms
3x^2-2x^2+4x-3x-1+2
x^2+x+1
