Gah, i'm beat i give up... i lose, maths wins

Can someone help me solve these?

1.) (X-1)/2 - (x-2)/3 = 1

2.) 2x/3x+1 = 0.85

3.) (2x - 1)/x = 1

4.) (x-1)(x+3) = 5

5.) -10x^2 +15

6.) 1/4 (x+1/2)^2 - 1/4

Could someone please leave working out and explanations particularly with the factorisation ones. Thanks, appreciate it.