Factorize the following algebraic expression by splitting the middle term:

$9a^2-6a+1$

Factorize the following algebraic expression by splitting the middle term:

$8x^2-22xy+15y^2$

Factorize the following algebraic expression by splitting the middle term:

$3a^2+11ab+6b^2$

Factorize the following algebraic expression by splitting the middle term:

$2a^2-17a-30$

Factorize the following algebraic expression by splitting the middle term:

$2{\left(3x-4y\right)}^2-3\left(3x-4y\right)-2$

Factorize the following algebraic expression by splitting the middle term:

$2x^2+7x-4$

Factorize the following algebraic expression by splitting the middle term:

$5a^2+13a+6$

Factorize the following algebraic expression by splitting the middle term:

$3{\left(2x-y\right)}^2+14\left(2x-y\right)+8$

Factorize the following by completing the squares:

$x^2+6x+8$