Question

(350 : b + 10) * 7 = 560

Answer 1

(350÷b+10)×7=560
350÷b+10=80
350÷b=70
b=5

Answer 2

$( \frac{350}{b} + 10) \times 7 = 560$
$\frac{350 + 10b}{b} \times 7 = 560$
$\frac{5(70 + 2b)}{5} \times 7 = 560$
$\frac{35(70 + 2b)}{b} = 560$
$2450 + 70b = 560b$
$490b = 2450$
$b = \frac{2450}{490}$
$b = 5$
Ответ: 5.