basically complete the square
so
conver tto y=a(x-h)²+k
steps:
group x terms
factor out leading coefient
take 1/2 of ilnear coefient and square it, add negative and positive inside
factor perfect square
expand/distribute
y=6x²+12x-10
group x
y=(6x²+12x)-10
factor out leading coefient
y=6(x²+2x)-10
take 1/2 of linear coefient and square it
2/2=1, 1²=1
add negativ and positivve inside
y=6(x²+2x+1-1)-10
factor perfect square
y=6((x+1)²-1)-10
distribute
y=6(x+1)²-6-10
y=6(x+1)²-16