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.
3 and 4! Because 3x4=12 and 4x3= 12! Mark me brainliest so I can help more people !
Step-by-step explanation:
<u>Given coordinates of the rectangle ABCD:</u>
- A(0, 0), B(a, 0), C(x, y), D(0, b)
Lets first find coordinates of C
We can see that A and B are on same line horizontally, so C and D will be on the parallel line
The distance AB and CD are equal also distance AD and BC are equal, therefore
- AB = a - 0 = a, CD = a
- AD = b - 0 = b, BC = b
<u>So the coordinates of C are:</u>
<u>Now the diagonals:</u>
- AC = √(a-0)² + (b-0)² = √a²+b²
- BD =√(0-a)² + (b -0)² = √a² + b²
Since AC = BD, we can state they are congruent
The zeroes are -1/2 and -2
last option
Answer:
#1 is the answere
Step-by-step explanation:
Check the sides
