Question

Помогите алгебра дам 50 баллов ​

Answer 1

$\frac{7x - 21}{10x + 50} \\ a) \: \: 10x + 50 = 0 \\ 10x = - 50 \\ x = - 50 \div 10 \\ x = - 5 \\ b) \: \: 7x - 21 = 0 \\ 7x = 21 \\ x = 21 \div 7 \\ x = 3$