Question

$q {?}^{2} - 10q + 21$

Answer 1

Heya user
Here is your answer !!

q^2 - 10q + 21
= q^2 - 7q - 3q + 21
= q (q-7) - 3 (q-7)
= (q-3) (q-7)
So , q is either 3 or 7 ( Ans ).

Hope it helps!!