A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 3 years ago
pleasee help!
Solve. x2  8x = 20
What are the solutions of 4x2  3x  5 = 0?
anonymous
 3 years ago
pleasee help! Solve. x2  8x = 20 What are the solutions of 4x2  3x  5 = 0?

This Question is Closed

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Simplifying x2 + 8x = 20 Reorder the terms: 8x + x2 = 20 Solving 8x + x2 = 20 Solving for variable 'x'. Reorder the terms: 20 + 8x + x2 = 20 + 20 Combine like terms: 20 + 20 = 0 20 + 8x + x2 = 0 Factor a trinomial. (2 + 1x)(10 + 1x) = 0 Subproblem 1Set the factor '(2 + 1x)' equal to zero and attempt to solve: Simplifying 2 + 1x = 0 Solving 2 + 1x = 0 Move all terms containing x to the left, all other terms to the right. Add '2' to each side of the equation. 2 + 2 + 1x = 0 + 2 Combine like terms: 2 + 2 = 0 0 + 1x = 0 + 2 1x = 0 + 2 Combine like terms: 0 + 2 = 2 1x = 2 Divide each side by '1'. x = 2 Simplifying x = 2 Subproblem 2Set the factor '(10 + 1x)' equal to zero and attempt to solve: Simplifying 10 + 1x = 0 Solving 10 + 1x = 0 Move all terms containing x to the left, all other terms to the right. Add '10' to each side of the equation. 10 + 10 + 1x = 0 + 10 Combine like terms: 10 + 10 = 0 0 + 1x = 0 + 10 1x = 0 + 10 Combine like terms: 0 + 10 = 10 1x = 10 Divide each side by '1'. x = 10 Simplifying x = 10Solutionx = {2, 10}

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Simplifying 4x2 + 3x + 5 = 0 Reorder the terms: 5 + 3x + 4x2 = 0 Solving 5 + 3x + 4x2 = 0 Solving for variable 'x'. Begin completing the square. Divide all terms by 4 the coefficient of the squared term: Divide each side by '4'. 1.25 + 0.75x + x2 = 0 Move the constant term to the right: Add '1.25' to each side of the equation. 1.25 + 0.75x + 1.25 + x2 = 0 + 1.25 Reorder the terms: 1.25 + 1.25 + 0.75x + x2 = 0 + 1.25 Combine like terms: 1.25 + 1.25 = 0.00 0.00 + 0.75x + x2 = 0 + 1.25 0.75x + x2 = 0 + 1.25 Combine like terms: 0 + 1.25 = 1.25 0.75x + x2 = 1.25 The x term is 0.75x. Take half its coefficient (0.375). Square it (0.140625) and add it to both sides. Add '0.140625' to each side of the equation. 0.75x + 0.140625 + x2 = 1.25 + 0.140625 Reorder the terms: 0.140625 + 0.75x + x2 = 1.25 + 0.140625 Combine like terms: 1.25 + 0.140625 = 1.390625 0.140625 + 0.75x + x2 = 1.390625 Factor a perfect square on the left side: (x + 0.375)(x + 0.375) = 1.390625 Calculate the square root of the right side: 1.179247642 Break this problem into two subproblems by setting (x + 0.375) equal to 1.179247642 and 1.179247642. Subproblem 1x + 0.375 = 1.179247642 Simplifying x + 0.375 = 1.179247642 Reorder the terms: 0.375 + x = 1.179247642 Solving 0.375 + x = 1.179247642 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.375' to each side of the equation. 0.375 + 0.375 + x = 1.179247642 + 0.375 Combine like terms: 0.375 + 0.375 = 0.000 0.000 + x = 1.179247642 + 0.375 x = 1.179247642 + 0.375 Combine like terms: 1.179247642 + 0.375 = 1.554247642 x = 1.554247642 Simplifying x = 1.554247642 Subproblem 2x + 0.375 = 1.179247642 Simplifying x + 0.375 = 1.179247642 Reorder the terms: 0.375 + x = 1.179247642 Solving 0.375 + x = 1.179247642 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.375' to each side of the equation. 0.375 + 0.375 + x = 1.179247642 + 0.375 Combine like terms: 0.375 + 0.375 = 0.000 0.000 + x = 1.179247642 + 0.375 x = 1.179247642 + 0.375 Combine like terms: 1.179247642 + 0.375 = 0.804247642 x = 0.804247642 Simplifying x = 0.804247642 SolutionThe solution to the problem is based on the solutions from the subproblems. x = {1.554247642, 0.804247642}

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0thanks so much you are a lifesaver!
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.