How do you solve #81x^2-10=-1#?

2 Answers
Jun 2, 2018

Answer:

#x=+-1/3#

Explanation:

#"isolate "81x^2" by adding 10 to both sides"#

#81x^2=-1+10=9#

#"divide both sides by 81"#

#x^2=9/81=1/9#

#color(blue)"take the square root of both sides"#

#sqrt(x^2)=+-sqrt(1/9)larrcolor(blue)"note plus or minus"#

#x=+-1/3#

Jun 2, 2018

Answer:

#x=pm1/3#

Explanation:

#81x^2=9#

#x^2=9/81#

#x=pmsqrt9/81#

#rArr pm3/9#

#rArr pm1/3#