{10(x+y)=30+8x
{9(x-y)=-49-8y
{10x+10y=30+8x
{9x-9y=-49-8y
{10x-8x+10y=30
{9x-9y+8y=-49
{2x+10y=30
{9x-y=-49|*10
2x+10y=30
90x-10y=-490
2x+90x=30-490
92x=-460|:92
x=-5
10*(-5)+10y=30+8*(-5)
-50+10y=30-40
10y=-10+50=10y=40:10
4=4
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ответ:(-5;4)
Пошаговое объяснение:
10(x+y)=30+8x
9(x-y)=-49-8
10x+10y=30+8x
9x-9y= -57
2x+10y=30
9x-9y= -57
18x+90y=270
-18x+18y=114
90y+18y=270+114
108y=384
y= 32/9
2x+10y=30
2x+10*32/9=30
2x+320/9=30
2x=30-320/9
2x= -50/9
x=-50/9 / 2
x= -25/9
x= -2 7/9
y=3 5/9
