А) 360 - (50 * 3 + 40 *3) = 90(м)
б) 360 + (50 * 3 + 40 * 3) = 630(м)
3/10 · 5/7 = (3·1)/(2·7) = 3/14.
Ответ: 3/14.
А) = 39 * (28 + 72) + 61 * (24 + 76) = 39 * 100 + 61 * 100 = 3 900 + 6 100 = 10 000
б) = 73 * (81 + 19) + 27 * (19 + 81) = 73 * 100 + 27 * 100 = 7 300 + 2 700 = 10 000
в) = 55 * (868 - 768) + 45 * (945 - 935) = 55 * 100 + 45 * 10 = 5 500 + 450 = 5 950
г) = 51 * (618 - 618) + 49 * (951 - 851) = 51 * 0 + 49 * 100 = 0 + 4 900 = 4 900
= 205 + в - 183 = 205 - 183 + в = 22 + в
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