y^2 + yt - 12t^2
`y^2 + yt - 12t^2`
You must use factors of the first term (`y^2)` which are y,y and cross multiply with the factors of the third term `-12t^2`
which are 1,12 and 2,6 and 3,4
Between the factors you must render the value of the middle term ,in this case 1yt.
Try: (y - 3t) and (y + 4t) as these are the only factors when cross multiplied that will give you 1yt.
`therefore` = (y-3t)(y+4t)