Solving Exponential Equations: Need Help Understanding 2 Questions

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In summary, the first question is asking for the simplification of the expression (2x+2)^2, which the answer is not correct. The second question is asking for the simplification of 84x/32x, which the answer is 27x.
  • #1
linapril
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I need help with understanding two questions:
1. (2x+2)2
The answer I got was: 22x+2x++4, but according to the answers that is wrong. Can any explain why?

2. 84x/32x
I simplified this to become (84/32)x, but I don't know how to go from there... The answer is apparently 27x, but I don't understand how that can be...

Would appreciate the help enormously,
//APRIL
 
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  • #2
Nevermind, I understood question 2 now, but question 1 is still a mystery to me...
 
  • #3
linapril said:
I need help with understanding two questions:
1. (2x+2)2
The answer I got was: 22x+2x++4, but according to the answers that is wrong. Can any explain why?

I think the middle term is wrong. The first and the last terms look good though. Check your work and if you still don't see it then post your attempt and we'll help you sort it out :)
 
  • #4
linapril said:
I need help with understanding two questions:
1. (2x+2)2
The answer I got was: 22x+2x++4, but according to the answers that is wrong. Can any explain why?

2. 84x/32x
I simplified this to become (84/32)x, but I don't know how to go from there... The answer is apparently 27x, but I don't understand how that can be...

Would appreciate the help enormously,
//APRIL

$\displaystyle \begin{align*} \left( 2^x + 2 \right)^2 &= \left( 2^x \right)^2 + 2\cdot 2\cdot 2^x + 2^2 \\ &= 2^{2x} + 2^{x + 2} + 2^2 \end{align*}$
 
  • #5


Hello April,

I can definitely help you understand these two questions about solving exponential equations.

First, let's take a look at the first question: (2x+2)^2. The answer you got, 22x+2x++4, is incorrect. When you have an exponential expression raised to a power, you need to use the exponent rule that states (a^b)^c = a^(b*c). In this case, that means we can rewrite the expression as (2x+2)(2x+2). Now, we can use the distributive property to simplify this further. We multiply the first term (2x) by both terms in the second parentheses (2x and 2) and then multiply the second term (2) by both terms in the second parentheses (2x and 2). This gives us 4x^2 + 4x + 4x + 4, which simplifies to 4x^2 + 8x + 4. Therefore, the correct answer is 4x^2 + 8x + 4.

Moving on to the second question: 84x/32x. You correctly simplified this to (84/32)x. Now, we need to simplify the fraction 84/32. We can do this by finding the greatest common factor (GCF) of both numbers, which is 4. We divide both numbers by 4 to get 21/8. Therefore, the expression becomes (21/8)x. And since 21 and 8 have no common factors, we cannot simplify this any further. The answer is simply (21/8)x or 2.625x.

I hope this explanation helps you understand how to solve these types of exponential equations. If you have any further questions, don't hesitate to ask. Keep up the good work!
 

FAQ: Solving Exponential Equations: Need Help Understanding 2 Questions

1. What is an exponential equation?

An exponential equation is an equation in which the variable appears in an exponent. It is typically written in the form y = ab^x, where a and b are constants and x is the variable.

2. How do I solve an exponential equation?

To solve an exponential equation, you can use logarithms. Take the logarithm of both sides of the equation and use the properties of logarithms to isolate the variable. Once the variable is isolated, you can solve for it by raising both sides to the appropriate power.

3. When do I need to use the logarithm property?

You need to use the logarithm property when the variable is in the exponent and you need to isolate the variable. Logarithms allow you to move the variable from the exponent to the base of the equation, making it easier to solve for the variable.

4. Can an exponential equation have more than one solution?

Yes, an exponential equation can have more than one solution. This is because raising a number to different powers can result in the same answer. Therefore, when using logarithms to solve an exponential equation, it is important to check your answer to make sure it is the only solution.

5. What are some real-life applications of exponential equations?

Exponential equations are commonly used in finance, biology, and physics. In finance, they can be used to calculate compound interest. In biology, they can be used to model population growth. In physics, they can be used to model radioactive decay and chemical reactions.

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