1)
25 * 3 * 4
45 * 2 * 5
16 : 4 * 5 * 10
8 * 12 * 100
2)
380 + 5 * (440 − 360)
(428 − 56 : 7) : 10
1)
25 * 3 * 4 = (25 * 4) * 3 = 100 * 3 = 300
45 * 2 * 5 = 45 * (2 * 5) = 45 * 10 = 450
16 : 4 * 5 * 10 = 4 * 5 * 10 = 20 * 10 = 200
8 * 12 * 100 = 96 * 100 = 9600
2)
$380 \overset{3}{+} 5 \overset{2}{*} (440 \overset{1}{-} 360) = 780$
1) 440 − 360 = 80
2) 5 * 80 = 400
3) 380 + 400 = 780
$(428 \overset{2}{-} 56 \overset{1}{:} 7) \overset{3}{:} 10 = 42$
1) 56 : 7 = 8
2) 428 − 8 = 420
3) 420 : 10 = 42
Ответ:
1)
25 * 3 * 4 = 300
45 * 2 * 5 = 450
16 : 4 * 5 * 10 = 200
8 * 12 * 100 = 9600
2)
380 + 5 * (440 − 360) = 780
(428 − 56 : 7) : 10 = 42