Question

spilt the term y2-4y-21​

Answer 1

y^2-(7-3)y-21

y^2-7y+3y-21

y(y-7)3(y-7)

(y+3) (y-7)

Answer 2

${y}^{2} - 4y - 21 = 0 \\ \\ {y}^{2} + 7y - 3y - 21 = 0 \\ \\ y(y + 7) - 3(y + 7) = 0 \\ \\ (y - 3)(y + 7) = 0 \\ \\ y = 3 \: or \: y = - 7$

HOPE IT HELPS YOU..❤