Question

factorisevy splitting middle term y^2+4y+21

Answer 1

$it \: is \: un \: factorizable \\ in \: place \: of \: 21 \: if \: it \: was \: - 21 \: then \: it \: can \: be \\ \\ {y}^{2} + 4y - 21 \\ {y}^{2} + 7y - 3y - 21 \\ y(y + 7) - 3(y + 7) \\ (y - 3)(y + 7)$