10-4(2x+5)=6y-13
4y-63=5(4x-2y)+2
4y-63-20x+10y-2=0
14y-65-20x=0
x=0.7y-3.25
3-8x-6y=0
3-8*(0.7y-3.25)-6y=0
3-5.6y+26-6y=0
29-11.6y=0
y=29/11.6y=2.пятых
14*2.5-65-20x=0
-30-20x=0
x=-30/20
x=-1.5
{2(5–y–z)–y+z=2
{3(5–y–z)–2y+z=1
{10–2y–2z–y+z=2
{15–3y–3z–2y+z=1
{–3y–z=–8
{–5y–2z=–14
{z=8–3y
{–5y–2(8–3y)=–14
–5y–16+6y=–14
y=2
z=8–3•2=2
x=5–2–2=1
ответ: (1;2;2)