How do you solve #3n ^ { 2} - 9n - 84= 0#?
1 Answer
Feb 16, 2018
An approach by middle term factor...
#3n^2-9n-84=0#
#=>3n^2+12n-21n-84=0#
#=>3n(n+4)-21(n+4)=0#
#=>(n+4)(3n-21)=0#
- Either,
#(n+4)=0=>color(red)(ul(bar(|color(green)(n=-4)|# - Or,
#(3n-21)=0=>3n=21=>color(red)(ul(bar(|color(green)(n=7)|# Graphical Representation:- graph{3x^2-9x-84 [-10, 10, -5, 5]}
Hope it helps...
Thank you...
