1) (-20-17.5)*(2.5-4.5) = -37.5*(-2) = 75
2) -20x-19*|y|-18 = ?
-20*(-8)-19*|-7|-18 = 160-19*7-18 = 160-133-18 = 27-18 = 9
3) 17/24+8/9*3/32 = 17/24 + (8*3)/(9*32) = 17/24 + 24/288 --> приводим к общему знаменателю 288 => 17*12/288 + 24/288 = 204/288 +24/288 = (204+24)/288 = 228/288
12·3х=12·3·х=36х 8t·12n=8·12·t·n=96tn
а) 1 1/3 б) 3 1/12 в) 5.5 г) 10 2/9 д) 4.25 в) 3 1/2
6*9=54
54:9=6
28:7=4
7*4=28
28:4=7
63:9=7
9*7=63
63:7=9