1. 2x^2+15x+5=0
D =b2 - 4ac = 152 - 4·2·5 = 225 - 40 = 185
x1 = (-15 - √185)/2·2 ≈ -7.1504
x2 = (-15 + √185)/2·2 ≈ -0.34963
2. 6x^2+13x+4=0
D =b2 - 4ac = 132 - 4·6·4 = 169 - 96 = 73
x1 = (-13 - √73)/2·6 ≈ -1.7953
x2 = (-13 + √73)/2·6 ≈ -0.37133
3. 5x^2+24x+9=0
D =b2 - 4ac = 242 - 4·5·9 = 576 - 180 = 396
x1 = (-24 - √396)/2·5 ≈ -4.38997487421324
x2 = (-24 + √396)/2·5 ≈ -0.4100251257867601
4. 7x^2-27x+12=0
D =b2 - 4ac = (-27)2 - 4·7·12 = 729 - 336 = 393
x1 = (27 - √393)/2·7 ≈ 0.51256
x2 = (27 + √393)/2·7 ≈ 3.3446
5. 4x^2+3x-2=0
D =b2 - 4ac = 32 - 4·4·(-2) = 9 + 32 = 41
x1 = (-3 - √41)/2·4 ≈ -1.1754
x2 = (-3 + √41)/2·4 ≈ 0.42539
6. 6x^2-10x-1=0
D =b2 - 4ac = (-10)2 - 4·6·(-1) = 100 + 24 = 124
x1 = (10 - √124)/2·6 =56 -16√31 ≈ -0.09462739380500358
x2 = (10 + √124)/2·6 = 56 + 16√31 ≈ 1.7612940604716705