Question

(66-x+13):7·10=30 помогите пожалуйств

Answer 1

$(66 - x + 13) \div 7 \times 10 = 30 \\ (79 - x) \div 7 \times 10 = 30 \\ (79 - x) \div 7 = 30 \div 1 0\\ (79 - x) \div 7 = 3 \\ 79 - x = 7\times 3 \\ 79 - x = 21 \\ x = 79 - 21 \\ x = 58$

Проверим:

$(66 - 58 + 13) \div 7 \times 10 = 30 \\ (8 + 13) \div 7 \times 10 = 30 \\ 21 \div 7 \times 10 = 30 \\ 3 \times 10 = 30 \\ 30 = 30$

Ответ: х = 58