2х+2х+1,5=х+3
3х=1,5
х=0,5
2х=2·0,5=1кг
1-0,5=0,5кг
0,5,·2=250грамов
100х=5.43
х=5,43:100
х=0,0543
Ответ:0,0543
1) -6(2a-7)+4(<span>5a-6) =-2 при a = -2,5
</span><span>2a-7= -2,5*2-7=-5-7=-12 -6*(-12)= +72
</span><span>5a-6= -2,5*5 -6= -12,5-6=-18,5 4*(-18,5) = -74
72+(-74)= - 2
2) -1,1(2m-4)-(2-3m)-0,4(1-m)=-0,8 при m=-4
</span>
<span>2m-4= -4*2-4= -8-4=-12 -1,1*(-12)= + 13,2
</span><span>2-3m= 2 -3*(-4)= 2+12=14
</span><span>1-m= 1 -(-4)= 1+4=5 0,4*5=2
13,2-12 - 2= 13,2-14=-0,8
3)1 1/9 (3y-9)- 8 1/3(y-6)= -8 при y = 3.6</span>
<span>3y-9= 3*3.6=10.8= 10 8/10=10 4/5= 54/5
1 1/9*10.8= 10/9* 54/5=12
</span>
<span>y-6= 3.6-6=-2.4= 2 4/10=2 2/5= 12/5
8 1/3= 25/3
</span>25/3*12/5=20
12-20=-8
A1=5, a2=2, a3=-1, a4=-4, a5=-7