Question

I don't know how to do it,so please help me to find the answer

Answer 1

(x - 7) (x - 9)
= x^2 - 9x - 7x + 63
= x^2 - 16x +63

Answer 2

Hey there!
Down here ⏬

$(x - 7) \: (x - 9)$


Equation in the form

$(x + a)(x + b) = x {}^{2} + (a + b)x + ab$

Where,

$x = x$

$a = ( - 7)$

$b = ( - 9)$

So,

$(x - 7)(x - 9) = x {}^{2} + (( - 7) + ( - 9)) \times x {}^{2} + ( - 7) \times ( - 9)$

$= x {}^{2} - 16x + 63$

Hope helped.