3. factor.
9x2 + 15x
(points : 1) x(3x + 5)
3x(3x + 5)
9x(x + 5)
3x2(3x + 5)
question 4.4. factor.
20mn − 30m
(points : 1) 2m − 3
10m(2n − 3)
10mn(2m + 3n)
10n(2m − 3) 5.5. factor.
8x2y2 − 4x2y − 12xy
(points : 1) 4(2xy − 4x2y − 12xy)
4(8x2y2 − x − 12xy)
4x2y2(2xy − xy −3)
4xy(2xy − x − 3)

It seems that some the work is already here, but I'd be glad to!! So for #3 which is 9x^2+15x, we can factor out both a 3 and an x (3x) so we know that 3x * 3x =9x^2 and 3x * 5 = 15x so once we take the 3x out of the equation, we are left with 3x(3x+5) and that's as far as you can factor.
For #4, we see that the common factor is 10m because 10m * 2n = 20mn and 10m * 3 = 30m so once we take 10m out of the original, it becomes 10m(2n-3)
For #5, this one the common factor is 4xy because 4xy * 2xy=8x^2y^2 and 4xy*x= 4x^2y and 4xy*3=12xy so once we take the 4xy out of the equation, it becomes 4xy(2xy-x-3)
Hope this helps!