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:
Option A. 3(n-2)
Step-by-step explanation:
"2 less" - "subtract 2"
Then 3 of n - 3n
Hope helps -
Answer:
Points P ( 4 , - 7 ) and Q ( 1 , 5 ) belong to the equations:
1 ; 4 ; and 5
Step-by-step explanation:
Equations 1 ; 4 and 5 are the same equation
Equation 1 y = - 4*x + 9
Equation 4
y + 7 = - 4 * ( x - 4 ) ⇒ y + 7 = - 4*x + 16 ⇒ y = - 4*x - 7 + 16
y = -4*x + 9
Equation 5
4*x + y = 9 ⇒ y = - 4*x + 9
Now for the equation y = - 4*x + 9
P ( 4 , -7)
For x = 4 y = - 4*(4) + 9 ⇒ y = - 16 + 9 ⇒ y = - 7
Then point P is in the line y = - 4*x + 9
Point Q (1 , 5 )
For x = 1 y = - 4 * ( 1) + 9 ⇒ y = - 4 + 9 ⇒ y = 5
Point Q is in the line y = - 4*x + 9
Equation 2
y = - 4*x - 23
Point P ( 4 , - 7 )
For x = 4 y = 16 - 23 y = - 7
Point P is in the line
Point Q
For x = 1 y = - 4 *(1) - 23 ⇒ y = - 27
Then poin Q is not in the line
Equation 3
y - 1 = - 4 * ( x - 4 )
y - 1 = -4*x + 16 ⇒ y = - 4*x + 17
Point P ( 4 , - 7 )
For x = 4
y = - 16 + 17 ⇒ y = 1
Point P is not in the line
And Point Q ( 1 , 5 )
For x = 1
y = - 4* ( 1 ) + 17 ⇒ y = 13 Q is not in the line
Answer:
5.5
Step-by-step explanation:
2 times 3 is 6 then but to the other side so plus 6 then You have 2y=11
then you dived it by two so 11 dived by 2 and you get 5.5
Answer:
Step-by-step explanation:
AB=-4-(-6)=2
DC=-4-(-6)=2
BC=-2-(-4)=2
AD=-2-(-4)=2
Perimeter=4*2=8 units
