Answer :

Answer:

The solution lie in  [tex](-\infty,1)\cup(7,\infty)[/tex]

Step-by-step explanation:

Given : Inequality [tex]x^2-8x+7>0[/tex]

To find : Solve the inequality?

Solution :

First we convert the inequality into equation,

[tex]x^2-8x+7=0[/tex]

Solving by middle term split,

[tex]x^2-7x-x+7=0[/tex]

[tex]x(x-7)-1(x-7)=0[/tex]

[tex](x-7)(x-1)=0[/tex]

[tex]x=7,1[/tex]

Use each root to create test intervals,

[tex]x<1\\1<x<7\\x>7[/tex]

For x<1, let x=0

[tex]0^2-8(0)+7>0[/tex]

[tex]0-0+7>0[/tex]

[tex]7>0[/tex]

True.

For 1<x<7, let x=3

[tex]3^2-8(3)+7>0[/tex]

[tex]9-24+7>0[/tex]

[tex]-8>0[/tex]

False.

For x>7, let x=8

[tex]8^2-8(8)+7>0[/tex]

[tex]64-64+7>0[/tex]

[tex]7>0[/tex]

True.

Therefore, The inequality form is x<1 or x>7.

The interval notation is [tex](-\infty,1)\cup(7,\infty)[/tex]

Other Questions