MHB Solving Exponential Equations: Need Help Understanding 2 Questions

  • Thread starter Thread starter linapril
  • Start date Start date
  • Tags Tags
    Exponential
Click For Summary
To solve the exponential equation (2^x + 2)^2, the correct expansion is 2^(2x) + 2^(x+2) + 4, which differs from the initial incorrect answer of 22x + 2x + 4. The middle term was identified as the source of confusion. For the second question, the simplification of 84x/32x to (84/32)x is correct, and it can be further simplified to 27x by reducing the fraction. Understanding these steps clarifies the solutions to both questions.
linapril
Messages
22
Reaction score
0
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
 
Mathematics news on Phys.org
Nevermind, I understood question 2 now, but question 1 is still a mystery to me...
 
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 :)
 
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

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

Thread 'Significant figures for inherently bound values'

I have been insisting to my statistics students that for probabilities, the rule is the number of significant figures is the number of digits past the leading zeros or leading nines. For example to give 4 significant figures for a probability: 0.000001234 and 0.99999991234 are the correct number of decimal places. That way the complementary probability can also be given to the same significant figures ( 0.999998766 and 0.00000008766 respectively). More generally if you have a value that...
View full post »

Similar threads

MHB Exponential Equation solve 54⋅2^(2x)=72^x⋅√0.5
  • · Replies 3 ·
Replies
3
Views
2K
MHB Quadratic equations ( solving for zeros/roots) trickey
  • · Replies 1 ·
Replies
1
Views
1K
I Finding the period in a modular exponentiation sequence
  • · Replies 1 ·
Replies
1
Views
1K
MHB Solving for an exponential equation using logarithms 16^{x}-5(4)^{x}-6=0
  • · Replies 3 ·
Replies
3
Views
2K
MHB Math Cumulative Review: Find the equation of a Line
  • · Replies 2 ·
Replies
2
Views
2K
MHB Solving Evaluate 3 * sqr(2): Understanding the Method
  • · Replies 3 ·
Replies
3
Views
2K
MHB Solve √(x^2+3x+7)-√(x^2-3x+9)+2=0
  • · Replies 5 ·
Replies
5
Views
2K
MHB Solving exponential (of trigonometric functions) equation
  • · Replies 1 ·
Replies
1
Views
2K
MHB Need help on these two questions
  • · Replies 8 ·
Replies
8
Views
1K
MHB Quadratic Equation Help: Find 3 Points to Determine Answer
  • · Replies 6 ·
Replies
6
Views
2K