Реши все примеры с объяснением

№12. \(D=b^2-4ac,\quad x=\dfrac{-b\pm\sqrt D}{2a}\)

1. \(D=144:\ x=2;\ -\frac25\)
2. \(D=64:\ x=\frac12;\ -\frac32\)
3. \(D=4:\ x=\frac12;\ \frac14\)
4. \(D=576:\ x=5;\ \frac15\)
5. \(D=196:\ x=5;\ -9\)
6. \(D=289:\ x=13;\ -4\)
7. \(D=529:\ x=5;\ -\frac83\)
8. \(D=2809:\ x=\frac{18}{5};\ -7\)
9. \(D=52:\ x=\frac{1\pm\sqrt{13}}{4}\)
10. \(D=153:\ x=\frac{1\pm\sqrt{17}}{6}\)
11. \(D=80:\ x=\frac{2\pm\sqrt5}{2}\)
12. \(D=28:\ x=\frac{-2\pm\sqrt7}{3}\)

№13.

1. \(7(x+2)=36\Rightarrow x=\frac{22}{7}\)
2. \(8x+2=48\Rightarrow x=\frac{23}{4}\)
3. \(7(5y-4)=2(16y+1)\Rightarrow y=10\)
4. \(5(19+3x)-8(1-9x)=0\Rightarrow x=-1\)
5. \(2x-5=22\Rightarrow x=\frac{27}{2}\)
6. \(\dfrac{3x-3}{2}=\dfrac{27}{8}\Rightarrow x=\frac{13}{4}\)

№14.

1. \(x^2-5x-24=0:\ x=-3;\ 8\)
2. \(3x^2-5x-50=0:\ x=5;\ -\frac{10}{3}\)
3. \(2x^2+2x-12=0:\ x=-3;\ 2\)
4. \(x^2-2x-15=0:\ x=-3;\ 5\)
5. \(x^2-10x+24=0:\ x=4;\ 6\)