Question

1) (5x-3)²-3(3+4x)=o
2) 2x²+x-5=0
3) X²-6x+13=0
решите уравнение

Answer 1

${(5x - 3)}^{2} - 3(3 + 4x) = 0 \\ 25 {x}^{2} - 30x + 9 - 9 - 12x = 0 \\ 25 {x}^{2} - 42x = 0 \\D = {( - 42)}^{2} - 4 \cdot 25 \cdot 0 = 1764 \\ \sqrt{D} = \sqrt{1764} = 42 \\ x_1 = \frac{42 + 42}{2 \cdot25} = \frac{84}{50} = 1.68 \\ x_2 = \frac{42 - 42}{2 \cdot25} = \frac{0}{50} = 0$