The answer is 68cm^2. Hope this helps!
Answer:
<em>t = 1.51</em>
Step-by-step explanation:
<u>Exponential Model</u>
The exponential model is often used to simulate the behavior of a magnitude that either grow or decay in proportion to the existing amount of that magnitude.
The model can be expressed as

In this case, Mo is the initial mass of the radioactive substance and k is a constant which value is positive if the mass is growing or negative if the mass is decaying.
The value of k is not precisely given in the question, we are assuming 
The model is now

We are required to compute the time it takes the mass to reach one-half of its initial value:

Simplifying

Taking logarithms

Solving for t

The area is 4 square meters, because 2x2 would be 4
The correct answer is 7. You add five to both sides then divide by three and you get 7 for x
Combining the like terms, the simplified polynomials are given as follows:
a) 4x² - 14x + 17
b) -5x² - 20x + 8
<h3>How are polynomials simplified?</h3>
Polynomials are simplified combining the like terms, that is, adding these numbers with the same variable.
Item a:
4(x - 2)(x + 1) - 5(2x - 5)
Applying the distributive property:
4(x² - x - 2) - 10x + 25
4x² - 4x - 8 - 10x + 25
Combining the like terms:
4x² - 4x - 10x - 8 + 25
4x² - 14x + 17
Item b:
-5(x + 2)² + 28
-5(x² + 4x + 4) + 28
-5x² - 20x - 20 + 28
-5x² - 20x + 8
More can be learned about the simplification of polynomials at brainly.com/question/24450834
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