SOLUTION: Please show me the step by step process to divide the following: 2x-6 over 21 divided by 5x-15 over 12. Thank you so much!

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Please show me the step by step process to divide the following: 2x-6 over 21 divided by 5x-15 over 12. Thank you so much!       Log On


   

Question 86115: Please show me the step by step process to divide the following:
2x-6 over 21 divided by 5x-15 over 12.
Thank you so much!
Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
[(2X-6)/21]/[(5X-15)/12] TO SIMPLIFY THIS PROCESS WE NEED TO INVERT THE DENOMINATOR AND THEN MULTIPLY.
[(2X-6)/21]
(2X-6)(5X-15)=12*21
10X^2-30X-30X+90=252
10X^2-60X+90-252=0
10X^2-60X-162=0
TO SOLVE THIS EQUATION WE NEED TO USE THE QUADRATIC EQUATION.
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
X=(60+-SQRT[-60^2-4*10*-162])/2*10
X=(60+-SQRT[3600+6480])/20
X=(60+-SQRT10080)/20
X=(60+-100.4)/20
X=(60+100.4)/20
X=160.4/20
X=8.02 ANSWER.
X=(60-100.4)/20
X=-40.4/20
X=-2.02 ANSWER.