Please help with factoring expressions completely?

1) 6a^2 - 8a - 30=2(3a^2-4a-15)=2(3a+5)(a-3) answer
2) 9a^2 + 24ab + 16b^2=(3a+4b)(3a+4b) answer
3) x^2 - 16y^2=(x+4y)(x-4y) answer//

1)
6a^2 - 8a - 30
= 2(3a^2 - 4a - 15)
= 2(3a^2 + 5a - 9a - 15)
= 2[(3a^2 + 5a) - (9a + 15)]
= 2[a(3a + 5) - 3(3a + 5)]
= 2(3a + 5)(a - 3)

2)
9a^2 + 24ab + 16b^2
= 9a^2 + 12ab + 12ab + 16b^2
= (9a^2 + 12ab) + (12ab + 16b^2)
= 3a(3a + 4b) + 4b(3a + 4b)
= (3a + 4b)(3a + 4b)
= (3a + 4b)^2

3)
a^2 - b^2 = (a + b)(a - b)
x^2 - 16y^2 = x^2 - (4y)^2 = (x + 4y)(x - 4y)

1) By factorization
6a^2 - 8a - 30 = 0
=> 6a^2 - 18a + 10a -30 = 0
=> 6a(a - 3) + 10(a - 3) = 0
=> (a - 3)(6a + 10) = 0
=> a - 3 = 0 or 6a + 10 = 0
=> a = 3 or 6a = -10
=> a = 3 or a = -10/6
=> a = 3 or a = -5/3

2) By Completing Square,
9a^2 + 24ab + 16b^2 = 0
=> (3a)^2 + 2(3a)(4b) + (4b)^2 = 0
=> (3a + 4b)^2 = 0
3) x^2 - 16y^2 = (x - 4y)(x + 4y)
Hope u get it
BEST OF LUCK
BYE

Answer:

1. ( a - 30 ) ( 6a + 10 )
2. ( 3a + 4b ) ( 3a + 4b )
3. ( x + 4y ) ( x - 4y )

1)
6a^2 - 8a - 30
Well, 2 can go into every term:
2 (3a^2 - 4 -15)
This reduces to:
2(3a + 5)(a - 3)

2)
9a^2 + 24ab + 16b^2
Well, looking at the variables it must be (xa + yb)(x + yb), you'll get:
(3a + 4b)(3a + 4b)
(3a + 4b)^2

3)
x^2 - 16y^2
Since there's no middle term (xy), the answer must look like (ax + by)(ax - by)
(x + 4)(x - 4y)

1) 2(3a+5)(a-3)
2) (3a+4b)^2
3) (x-4y)(x+4y)

1. 2(3a^2 - 4a - 15)
.....2(3a + 5)(a - 3)

2. (3a + 4b)^2

3. (x - 4y)(x + 4y)