Sin = -12/13
ctg=cos/sin= -(5/13)/(12/13)=-5/12
<span>(11/18+2/9):5/48=(11/18+4/18):5/48=15/18*48/5=720/90=8</span>
{y-2x=4/*(-5)⇒-5y+10x=-20
{5y-3x=-2
прибавим
7x=-22
x=-22/7
y-2*(-22/7)=4
y=4-6 2/7=-2 2/7
x-4y=-22/7-4*(-16/7)=-22/7+64/7=34/7=4 6/7
1. 0,08
2. 3,49
3. b(-31a^2 + 6)
4. 12,4
5. 1,2mn-3n; 0,5tu-0,5u; b-bt