Expand the expression?
Perform indicated multiplication:
7a(2a)+7a(-5)-4(2a)-4(-5)
14a^2-35a-8a+20 combine like terms, ie (-35a-8a)=-43a
14a^2-43a+20
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Hello!</h2>
The answer is: 23.77 hours
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Why?</h2>

Where:
Total(t) is equal to the amount for a determined time (in hours)
<em>Start</em> is the original amount
<em>t </em>is the time in hours.
For example, it's known from the statement that the bacteria double their population every 15 hours, so it can be written like this:

To calculate how long it takes for the bacteria cells to increase to 300, we should do the following calculation:

So, to know if we are right, let's replace 23.77 h in the equation:
Total(t)=100*2^\frac{23.77}{15}=299.94
and 299.94≅300
Have a nice day!
Hopes this helps:
Answer: x = 6
Answer:
1
Step-by-step explanation:
Given the system of equations below
y=2x+5
y=x+6
Equating the right hand side of the expressions we will have;
2x+5 = x+6
Collect the like terms;
2x - x = 6 - 5
x = 1
Hence the x-coordinate of the solution to the system is 1
1) 2 1/3 is also equal to 7/3
4 1/5 is also equal to 21/5
you need to make the denominators the same so you have to find the lowest common multiple, which is 15 since both 5 and 3 can be times by to make 15
you need to also times the numerators by the number you're timesing the denominator by
7/3 x 5 = 35/15
21/5 x 3 = 63/15
now add those together
35/15 + 63/15 = 98/15
now just convert 98/15 back to a mixed fraction
98/15 = 6 8/15
the answer is..

I'll do the others in a different answer!!