(3a+7)/(a+4) >= 0

I forgot the step to solve the problem , please help me !!!(Crying)

Printable View

- Feb 20th 2011, 05:19 AMhoanghai549Solve the following inequality
(3a+7)/(a+4) >= 0

I forgot the step to solve the problem , please help me !!!(Crying) - Feb 20th 2011, 05:35 AMPlato
- Feb 20th 2011, 05:41 AMhoanghai549
So It means I have to solve the two above conditions or just use the one thing ?

- Feb 20th 2011, 05:52 AMPlato
- Feb 20th 2011, 05:54 AMhoanghai549
nice thanks for your help

- Feb 20th 2011, 07:14 AMArchie Meade
deleted

- Feb 20th 2011, 03:45 PMPlato
Look at the numerator and the denominator.

If both have the same sign then the inequality is true.

It is easy to see that if $\displaystyle a<-4$ then both are negative.

If $\displaystyle a\ge -\frac{7}{3}$ then both are non-negative.

Write the solution set as $\displaystyle (-\infty,-4)\cup\left[-\frac{7}{3},\infty\right)$.

There is no complicated calculation necessary.