Question

Помогите пожалуйста!!!​

Answer 1

$\frac{ {x}^{2} + 10x }{10} - \frac{2x + 5}{2} = 20 \: \: \: | \times 10 \\ {x}^{2} + 10x - 5(2x + 5) = 200 \\ {x}^{2} + 10x - 10x - 25 = 200 \\ {x}^{2} - 25 - 200 = 0 \\ {x}^{2} - 225 = 0 \\ {x}^{2} - 15 {}^{2} = 0 \\ (x - 15)(x + 15) = 0 \\ x_{1} = 15 \\ x_{2} = - 15$