Explanation:
for Q9i
(x-3)(x-7)
let (x-3)= a, (x-7)=b
opening the bracket by multiplying bracket a by bracket b
we have x²-7x-3x+21
x²-10x+21
Q9ii (x+1)(3x+2)=x²+2x+3x+2= x²+5x+2
the two answer can be solved by using this formula x=-b±✓b²-4ac
---------------
2a