A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 3 years ago
Solve. x2  10x = 21
anonymous
 3 years ago
Solve. x2  10x = 21

This Question is Closed

mathstudent55
 3 years ago
Best ResponseYou've already chosen the best response.0First, add 21 to both sides. Once you have all three terms on left side equaling zero on right side, try to factor the left side. Then set each factor equal to zero and solve both equations. If you can't factor it, the use the quadratic formula.

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Simplifying x2 + 10x = 21 Reorder the terms: 10x + x2 = 21 Solving 10x + x2 = 21 Solving for variable 'x'. Reorder the terms: 21 + 10x + x2 = 21 + 21 Combine like terms: 21 + 21 = 0 21 + 10x + x2 = 0 Factor a trinomial. (3 + 1x)(7 + 1x) = 0 Subproblem 1Set the factor '(3 + 1x)' equal to zero and attempt to solve: Simplifying 3 + 1x = 0 Solving 3 + 1x = 0 Move all terms containing x to the left, all other terms to the right. Add '3' to each side of the equation. 3 + 3 + 1x = 0 + 3 Combine like terms: 3 + 3 = 0 0 + 1x = 0 + 3 1x = 0 + 3 Combine like terms: 0 + 3 = 3 1x = 3 Divide each side by '1'. x = 3 Simplifying x = 3 Subproblem 2Set the factor '(7 + 1x)' equal to zero and attempt to solve: Simplifying 7 + 1x = 0 Solving 7 + 1x = 0 Move all terms containing x to the left, all other terms to the right. Add '7' to each side of the equation. 7 + 7 + 1x = 0 + 7 Combine like terms: 7 + 7 = 0 0 + 1x = 0 + 7 1x = 0 + 7 Combine like terms: 0 + 7 = 7 1x = 7 Divide each side by '1'. x = 7 Simplifying x = 7Solutionx = {3, 7}

mathstudent55
 3 years ago
Best ResponseYou've already chosen the best response.0x^2  10x = 21 Add 21 to both sides: x^2  10x + 21 = 0 Factor left side: (x  7)(x  3) = 0 Set each factor equal to zero and solve: x  7 = 0 or x  3 = 0 x = 7 or x = 3
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.