Question

X^2−4x−21 I need help with this question and please right every step of it

Answer 1

`\boxed{ \boxed{ \sf{ \bold{( x - 7)(x + 3)}}}}`

Explanation:

`\sf{ {x}^(2) - 4x - 21}`

Here, we have to find the two numbers that subtracts to 4 and multiplies to 21

⇒
`\sf{ {x}^(2) - (7 - 3)x - 21}`

⇒
`\sf{ {x}^(2) - 7x + 3x - 21}`

Factor out X from the expression

⇒
`\sf{ x(x - 7) + 3x - 21}`

Factor out 3 from the expression

⇒
`\sf{x(x - 7) + 3(x - 7)}`

Factor out x-7 from the expression

⇒
`\sf{(x - 7)(x + 3)}`

Hope I helped!

Best regards!!

Answer 2

`\boxed{\boxed{\bold{(x - 7)(x + 3)}}}`

Explanation:

`{x}^(2) - 4x - 21 \\ {x}^(2) - 7x + 3x - 21 \\ x(x - 7) + 3(x - 7) \\ (x - 7)(x + 3)`