<span>(1-3х)(1-4х+х²)+(3х-1)(1-5х+х²)+3х²=
=</span>(1-3х)(1-4х+х²)-(1-3x)(1-5x+x²)+3x²=
=(1-3x)(1-4x+x²-1+5x-x²)+3x²=
=(1-3x)*x+3x²=x-3x²+3x²=x
<span>x/12+х/8+х= 29/6
2x/24+3x/24+24x/24=116/24
2x+3x+24x=116
29x=116
x=116/29
x=4
</span><span>
</span>
5x+6=12,5x
5x-12,5x=6
7,5x=6
x=6:7,5
x=-1,25
1) 0,57:0,3=1,9
2)3,7-1,9=1,8
Ответ : 1,8