Options :
A. The initial number of bacteria is 7.
B. The initial of bacteria decreases at a rate of 93% each day.
C. The number of bacteria increases at a rate of 7% each day.
D. The number of bacteria at the end of one day is 360.
Answer:
C. The number of bacteria increases at a rate of 7% each day.
Step-by-step explanation:
Given the function :
f(x)=360(1.07)^x ; Number of bacteria in sample at the end of x days :
The function above represents an exponential growth function :
With the general form ; Ab^x
Where A = initial amount ;
b = growth rate
x = time
For the function :
A = initial amount of bacteria = 360
b = growth rate = (1 + r) = 1.07
If ; (1 + r) = 1.07 ; we can solve for r to obtain the daily growth rate ;
1 + r = 1.07
r = 1.07 - 1
r = 0.07
r as a percentage ;
0.07 * 100% = 7%
2/4 this is a half also known as 1/2 Hope this helps!!!!!!!!!!!!!!!!!!!!!!!!
The answer is x = 10, y = 10.
Step 1: rearrange the second equation for y.
Step 2: substitute y from the second equation into the first equation.
Step 3. Calculate y.
Step 1.
<span>The second equation is: 6x + 3y = 90
Divide both sides of the equation by 3:
(6x + 3y)/3 = 90/3
6x/3 + 3y/3 = 30
2x + y = 30
Rearrange the equation:
y = 30 - 2x
Step 2.
</span>Substitute y from the second equation (y = 30 - 2x) into the first equation:
<span>15x + 9y = 240
15x + 9(30 - 2x) = 240
15x + 270 - 18x = 240
15x - 18x = 240 - 270
-3x = -30
x = -30/-3
x = 10
Step 3.
Since </span>y = 30 - 2x and x = 10, then:
y = 30 - 2 * 10
y = 30 - 20
y = 10
Answer:
The actual wide of the lawn is 24 meters
Step-by-step explanation:
we know that
The scale drawing is
using proportion
Find out how wide is the actual lawn if the lawn is 48 millimeters in the drawing
Let
x -----> the actual wide of the lawn
therefore
The actual wide of the lawn is 24 meters
Answer:
13 l of 15%, 13 l of 25%, 26 l of 70%
Step-by-step explanation:
solutions:
final solution:
This includes 0.45*52l= 23.4 l acid
Let's assume:
- amount of 15% solution= x
- amount of 25% solution= y
- amount of 70% solution= z
- and we have z=2y
so there are 2 equation:
or
- x+y+2y= 52 ⇒ x+3y= 52 ⇒ x= 52- 3y
- 0.15x+1.65y=23.4
- 0.15*(52-3y)+1.65y=23.4
- 7.8-0.45y+1.65y=23.4
- 1.2y=23.4-7.8
- 1.2y= 15.6
--------
- x= 52- 3*13= 13 l
- z= 2y= 2*13= 26 l
