factorise

1. 3a^2 - 2a - 8

2. 3x^2 + 31 + 10

3. 64y^2 - 49

please help

thankyou

well, 6 and 4 differ by 2

so
(3a+4)(a-2)

I need 30 and 1 so
(3x+1)(x+10)

difference of 2 squares
a^2-b^2 = (a-b)(a+b)
here a = 8y and b = 7