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:
Supplementary angles are two angles whose sum is 180 degrees while complementary angles are two angles whose sum is 90 degrees.
Step-by-step explanation:
Answer: For 10 sessions, the cost of the two plans the same.
Step-by-step explanation:
Let x= Number of sessions.
Given: Christian’s Gym charges a one-time fee of $50 plus $30 per session for a personal trainer.
Total charge for x sessions = 50+30x
Nicole's fitness center charges a yearly fee of $250 plus $10 for each session with a trainer.
Total charge for x sessions = 250+10x
When both plan charges the same, then
i.e. For 10 sessions, the cost of the two plans the same.
Answer:
x = (y+w)/k
Step-by-step explanation:
xk-w=y
Add w to each side
xk-w+w=y+w
xk = y+w
Divide each side by k
xk/k = (y+w)/k
x = (y+w)/k
