Respuesta :
To find the final term to compete the square you need to divide the 'x' term by 2 then square it
[tex]x^2 +18x + = 44+ \\ x^2+18x+( \frac{18}{2} )^2=44+( \frac{18}{2} )^2 \\ x^2+18x+9^2=44+9^2 \\ x^2+18x+81=44+81 \\ (x+9)^2=125[/tex] - equivalent equation
[tex]x^2 +18x + = 44+ \\ x^2+18x+( \frac{18}{2} )^2=44+( \frac{18}{2} )^2 \\ x^2+18x+9^2=44+9^2 \\ x^2+18x+81=44+81 \\ (x+9)^2=125[/tex] - equivalent equation
Answer:
The value of x are 2.18 and -20.8.
Step-by-step explanation:
Given : Equation [tex]x^2+18x=44[/tex]
To find : What values make an equivalent number sentence after completing the square?
Solution :
Equation [tex]x^2+18x-44=0[/tex]
Applying completing the square,
Step 1 - Make the coefficient of x be 1
[tex]x^2+18x-44=0[/tex]
Step 2 - Add and subtract the square of half of the coefficient of x
i.e. square of 9
[tex]x^2+18x-44+9^2-9^2=0[/tex]
Step 3 - Form the identity [tex](a^2+2ab+b^2)=(a+b)^2[/tex]
[tex]x^2+2.9.x+9^2-44-81[/tex]
[tex](x+9)^2-125=0[/tex]
Completing the square form of the given equation is [tex](x+9)^2-125=0[/tex]
Now, we solve for x
[tex](x+9)^2=125[/tex]
[tex]x+9=\sqrt{125}[/tex]
[tex]x+9=\pm 11.18[/tex]
[tex]x=\pm 11.18-9[/tex]
[tex]x=11.18-9,-11.8-9[/tex]
[tex]x=2.18,-20.8[/tex]
Therefore, The value of x are 2.18 and -20.8.