k21214
k21214 k21214
  • 02-05-2014
  • Mathematics
contestada

How do you solve x²-10x+9=0 by completing the square?

Respuesta :

Аноним Аноним
  • 02-05-2014
[tex]x^2-10x+9=0\\\\\underbrace{x^2-2x\cdot5+5^2}_{(*)}-5^2+9=0\\\\(x-5)^2-25+9=0\\\\(x-5)^2-16=0\ \ \ /+16\\\\(x-5)^2=16\iff x-5=-\sqrt{16}\ \vee\ x-5=\sqrt{16}\\\\x-5=-4\ \vee\ x-5=4\\\\x=-4+5\ \vee\ x=4+5\\\\x=1\ \vee\ x=9[/tex]



[tex](*)\ (a-b)^2=a^2-2ab+b^2[/tex]
Answer Link
kate200468
kate200468 kate200468
  • 03-05-2014
[tex]x^2-10x+9=0 \\ \\x^2-2\cdot5x+5^2-5^2+9=0\\ \\(x-5)^2-25+9=0\\ \\(x-5)^2=16\\ \\x-5=4\ \ \vee\ \ x-5=-4\\ \\x=9\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x=1[/tex]
Answer Link

Otras preguntas

What is the product of (x+1) and (2x^2+3x-1)?
What is 68 divided by the square root of 4
Which of the following categories includes the most distantly related organisms? (A) family (B) species (C) class (D) genus (E) order
how many books did Harriet beecher stowe write?
what are some reasons for limiting authority
Which of the following categories includes the most distantly related organisms? (A) family (B) species (C) class (D) genus (E) order
Many colonial people volunteered to fight for the Allied forces because they hoped their service would win their colony's ____
A mouse population starts with 2,000 mice and grows at a rate of 5% per year. The number of mice after t years can be modeled by the equation, P(t)=2000(1.05)^t
Help??? What is 3x+5x=67y?
How can b^2+9b+14 be re-written?1) (b+7) (b-7)2) (b-7) (b-2)3) (b+7) (b-2)4) (b+7) (b+2)