Question

factorise X *2 + 4 - 21 is equals to zero​

Answer 1

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

Hope it helps.

Answer 2

Answer:hope it helps you

Step-by-step explanation: