Question

помогите решить !!!!номер 10,11​

Answer 1

$10.$

$a) \: \: \: \: \: 642 \times x$

$x = 407 \: ; \: 4070 \: ; \: 40700$

$642 \times 407 = 261294$

$642 \times 4070 = 2 612 940$

$642 \times 40700 = 26 129 400$

$б) \: \: \: \: \: y \div 5$

$y = 1030 \: ; \: 10300 \: ; \: 103000$

$1030 \div 5 =206$

$10300 \div 5 = 2060$

$103000 \div 5 = 20600$

$11.$

$a)$

$(32 - x) \times 6 - 39 = 45 \\ 192 - 6x - 39 = 45 \\ 153 - 6x = 45 \\ - 6x = 45 - 153 \\ - 6x = - 108 \\ x = 18$

Проверка:

$(32 - 18) \times 6 - 39 = 14 \times 6 - 39 = 84 - 39 = 45$

$б)$

$(275 + 80 \div y) \div 4 = 70 \\ 275 + \frac{80}{y} = 70 \times 4 \\ \frac{275y + 80}{y} = 280 \\ 275y + 80 = 280y \\ 280y - 275y = 80 \\ 5y = 80 \\ y = 16$

Проверка:

$(275 + 80 \div 16) \div 4 = (275 + 5) \div 4 = 280 \div 4 = 70$