Respuesta :
Answer
[tex]|x-7|=5[/tex]
Explanation
We know that we need to write our absolute value equation as [tex]|x-b|=c[/tex]. We also know that the solutions must be [tex]x=2[/tex] and [tex]x=12[/tex]. We need to replace those values for [tex]x[/tex] in our absolute value equation, so we can create a system of equations and find the values of [tex]b[/tex] and [tex]c[/tex].
- For [tex]x=2[/tex]
[tex]|x-b|=c[/tex]
[tex]|2-b|=c[/tex] equation (1)
- For [tex]x=12[/tex]
[tex]|x-b|=c[/tex]
[tex]|12-b|=c[/tex] equation (2)
Now we can solve our system of equations step-by-step:
Step 1. Replace equation (1) in equation (2)
[tex]|12-b|=|2-b|[/tex]
Step 2. Square both sides of the equation to get rid of the absolute values
[tex]|12-b|=|2-b|[/tex]
[tex](12-b)^2=(2-b)^2[/tex]
Step 3. Use the square of a binomial formula: [tex](a-b)^2=a^2-2ab+b^2[/tex] and solve the equation.
For our first binomial, [tex](12-b)^2[/tex], [tex]a=12[/tex] and [tex]b=b[/tex]; for our second binomial, [tex](2-b)^2[/tex], [tex]a=2[/tex] and [tex]b=b[/tex]
[tex](12-b)^2=(2-b)^2[/tex]
[tex]12^2-(2)(12)(b)+b^2=2^2-(2)(2)(b)+b^2[/tex]
[tex]144-24b+b^2=4-4b+b^2[/tex]
[tex]144-24b=4-4b[/tex]
[tex]140=20b[/tex]
[tex]b=\frac{140}{20}[/tex]
[tex]b=7[/tex] equation (3)
Step 4. Replace equation (3) in equation (2) to find the value of [tex]c[/tex]
[tex]|12-b|=c[/tex]
[tex]|12-5|=c[/tex]
[tex]|7|=c[/tex]
[tex]c=7[/tex]
Putting it all together we can conclude that our absolute value equation is [tex]|x-7|=5[/tex]