SOLUTION: Use the quadratic formula to solve: 7x2 = -12x - 2

Algebra ->  Linear-equations -> SOLUTION: Use the quadratic formula to solve: 7x2 = -12x - 2      Log On


   

Question 1153959: Use the quadratic formula to solve: 7x2 = -12x - 2
Found 2 solutions by MathLover1, ikleyn:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

7x%5E2+=+-12x+-+2
7x%5E2%2B12x+%2B2=0

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-12+%2B-+sqrt%28+12%5E2-4%2A7%2A2+%29%29%2F%282%2A7%29+
x+=+%28-12+%2B-+sqrt%28+144-56+%29%29%2F14+
x+=+%28-12+%2B-+sqrt%28+88%29%29%2F14+
x+=+%28-12+%2B-+2sqrt%2822%29%29%2F14+
x+=+%28-6+%2B-+sqrt%2822%29%29%2F7+
solutions:
x+=+%28-6+%2B+sqrt%2822%29%29%2F7+ =>x+=+-6%2F7+%2B+sqrt%2822%29%2F7+ => approximately -0.2
x+=+%28-6+-+sqrt%2822%29%29%2F7+ =>x+=+-6%2F7+-sqrt%2822%29%2F7+ => approximately -1.5

+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+7x%5E2%2B12x+%2B2%29+





Answer by ikleyn(52786) About Me  (Show Source):
You can put this solution on YOUR website!
.

Solving quadratic equations is a  BASIC  ELEMENTARY  SKILL  each student  MUST  DEVELOPE  in his  (or her)  school years.

To help the students,  the lessons were created in this site
    - Introduction into Quadratic Equations
    - PROOF of quadratic formula by completing the square
giving the general theory and examples.

Read them and learn on how to solve quadratic equations using the quadratic formula on your own,  once and for all.

Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic "Quadratic equations".


Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.