Solving Inequalities

[asissa]

Hi - my kids didn't understand the explanation for this in class, and I'm at a loss to explain - help please.

Solve: x^2+5x-7<=4x

We have solved it to: (x-1)(x+7)<=4x
Does one move the 4x over first?

Please explain.

Thank you

 

[Deleted member 4993]

Hi - my kids didn't understand the explanation for this in class, and I'm at a loss to explain - help please.

Solve: x^2+5x-7<=4x

We have solved it to: (x-1)(x+7)<=4x .... (x-1)(x+7) = x[sup:3uyzem0s]2[/sup:3uyzem0s] + 6x - 7 not the polynomial you posted (x^2 + 5x -7)

Does one move the 4x over first? Yes

Please explain.

Thank you

\(\displaystyle x^2 \ + \ 5x \ - \ 7 \ \le 4x\)

\(\displaystyle x^2 \ + \ 5x \ - \ 7 \ - \ 4x \ \le \ 0\)

\(\displaystyle x^2 \ + \ x \ - \ 7 \ \le \ 0\)

Now you can find the roots through quadratic formula

 

[asissa]

Thank you!