1) 6 * 35 = 6* (5*7) = 210
2) 5 * 18 = 5* (2*9) = 90
3) 15 * 12 = 15* (4*3) = 180
4) 8 * 25 = 8* (5*5) = 200
1)5/8=х/24
8х=24*5
8х=120
Х=120:8
Х=15
2)6/х=36/24
36х=24*6
36х=144
Х=144:36
Х=4
3)13/х=39/36
39х=36*13
39х=468
Х=468:39
Х=12
4)х/7=12/21
21х=7*12
21х=84
Х=84:21
Х=4
5)34/45=х/5
45х=5*34
45х=170
Х=170:45
Х=3 7/9
6)25/4=75/х
25х=75*4
25х=300
Х=300:25
Х=12
6а²-(9а²-5аb)+(3a²-2ab) = 6а²-9а²+5аb+3a²-2ab = 3ab
при а = -0,15; <span>b=6
</span>3ab = 3*(-0,15)*6 = -2,7
1) 6км-380м=5км620м; 2ц50кг*4=8ц200кг=10ц=1т; 2ч30мин:5=150мин:5=0,5ч=30мин; 4дм2+38см2=4,38дм2=438см2.