Chapter 9.2, Problem 16E

To determine

To solve the equation by graphing

Answer to Problem 16E

The solution is $x=-1,x=7$

Explanation of Solution

Given information:

  $x^2-6x-7=0$

Calculation:

The given equation is $x^2-6x-7=0$

To solve the solution, take $y=x^2-6x-7$

Solve by putting values of x .

For $x=1$

  $y=1^2-6(1)-7$

Solving,

  $y=-12$

For $x=-1$

  $y={(-1)}^2-6(-1)-7$

Solving,

  $y=1+6-7$ = 0

For $x=7$

  $y=7^2-6(7)-7$

Solving,

  $y=49-42-7=0$

For $x=0$

  $y={(0)}^2-6(0)-7$

Solving,

  $y=-7$

Table is

$x$	1	-1	7	0
$y$	-12	0	0	-7

Graph:

  

Interpretation:

The point where y= 0 are the solution of the graph. Hence, the solution is $x=-1,x=7$