Question

[(b-800):500+900]:250=4​

Answer 1

$[(b - 800) : 500 + 900] : 250 = 4 \\ (b - 800) : 500 + 900 = 4 \times 250 \\ (b - 800) : 500 + 900 = 1000 \\ (b - 800) : 500 = 1000 - 900 \\ (b - 800) : 500 = 100 \\ b - 800 = 100 \times 500 \\ b - 800 = 50000 \\ b = 50000 + 800 \\ b = 50800$