Sin(α+β) - sin(α-β) = sinαcosβ + sinβcosα - sinαcosβ + sinβcosα = 2cosαsinβ
1)13х-1609=1307-14х,
13х+14х=1307+1609,
27х=2916
х=108
2) 21-(5х-11)=12
21-5х+11=12
5х=21+11-12
5х=20
<span> х=4
3)
</span>
<span>10*(1530-х)=5300
</span> 15300-10х=5300
15300-5300=10х
10000=10х
<span> х=1000</span>
Пошаговое объяснение:
111530 - 2130 * (524 - 348) : 4 = 17810
1) 524 - 348 = 176
2) 2130 * 176 = 374880
3) 374880 : 4 = 93720
4) 111530 - 93720 = 17810
12.7+9.6-4.3+2.7=22.3-4.3+2.7=18+2.7=20.7