Need Help with Math quick

Question

1. 2x^2 -5=20
2. x2+4x=12
3. x2=3x+5=0
4. x2=6x

Answer 1

1 x = + or - sqr(25/2) = +/-5/sqr2 = +/-2.5sqr2

2 x^2+ 4x -12=0

(x+6)(x-2) = 0

x = -6 pr =2

3 x^2 -3x +5 = 0

x = 3/2 + or - .5sqr(9 -20) = 1.5+/-.5isqr11

4 x^2 = 6x, x =6 or 0