let n = 2.5. what is the value of 2n(6n-3)+4n?
\(2n(6n-3)+4n\)substitute \(n=2.5\)\(2*2.5(6*2.5-3)+4*2.5=5(15-3)+10=60+10=70\)
\(n = 2.5, \ \\\\\ 2n(6n-3)+4n = 12n^2 - 6n +4n =12n^2-2n\\ \\12n^2-2n=12 *(2.5)^2-2*2.5=12*6.25-5=75-5=70\)
