radomes.openskiesproject.org
k21214
k21214 k21214
  • 01-05-2014
  • Mathematics
Answered

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

Verified Answer :

Anonymous Anonymous
  • 01-05-2014

\(x^2-10x+9=0\\\\\underbrace{x^2-2x\cdot5+5^2}_{(*)}-5^2+9=0\\\\(x-5)^2-25+9=0\\\\(x-5)^2-16=0\ \ \ /+16\\\\(x-5)^2=16\iff x-5=-\sqrt{16}\ \vee\ x-5=\sqrt{16}\\\\x-5=-4\ \vee\ x-5=4\\\\x=-4+5\ \vee\ x=4+5\\\\x=1\ \vee\ x=9\)



\((*)\ (a-b)^2=a^2-2ab+b^2\)

Answer Link
kate200468
kate200468 kate200468
  • 02-05-2014

\(x^2-10x+9=0 \\ \\x^2-2\cdot5x+5^2-5^2+9=0\\ \\(x-5)^2-25+9=0\\ \\(x-5)^2=16\\ \\x-5=4\ \ \vee\ \ x-5=-4\\ \\x=9\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x=1\)

Answer Link

Related Questions

multi step equations solve the equation
Read the phrase from the passage and answer the question that follows He must have tried it a hundred times shut his eyes so that he wouldnt have to look at the
How would you write 37025 in word form
what did karl marx do for the russian revolution
What is the constant of proportionality of a graph if x equals 3 and y equals 90
what is the density of a orange if its mass is 1582 g and the volume is 106 mL
why did florence enjoy a flourishing of the arts in the 1400s
What were the cause of the american boom in the 1950s how did prosperity affect the nation socially politically and economically Provide evidence
What 1679 equal
In a parallelogram if the measure of y is 32 degrees what is the measure of w