
30.
ա) x=+2y
2(2y)-3y-7=0
4y-3y-7=0
y=+7
x=2y
x=2(7)
x=14
բ) x=-5y
3(-5y)+7y-16=0
-15y+7y=+16
-8y=+16
-y=+2
y=-2
x=-5(-2)
x=+10
գ) y=+3x
x-2(+3x)+10=0
x-6x=-10
-5x=-10
-x=-2
x=2
y=+3(2)
y=6
դ) y=+7x
3x-7x+12=0
-4x=-12
-x=-3
x=+3
y=+7(3)
y=21
31.
ա)x=+y+1
y+1+y-5=0
2y=-1+5
2y=4
y=2
x=2+1
x=3
բ)x=+4+2
y+2+y-6=0
2y=4
y=2
x=2+2
x=4
գ)x=y+2
3(y+2)-2y-9=0
3y+6-24-9=0
y=-6+9
y=3
x=3+2
x=5
д)x=2y+3
5(2y+3)+y-4=0
10y+15+y-4=0
11y=-15+4
11y=-11
y=-1
x=2(-1)+3
x=-2+3
x=1

ե) x=-2y+11
4(-2y+11)-5y+8=0
-8y+44-5y+8=0
-8y-5y=-44-8
-13y=52
y=4
x=-2(4)+11
x=-8+11
x=3
զ) x=-4y+2
3(-4y+2)+8y-2
-12y+6+8y-2=0
-12y+8y=-6+2
-4y=-4
y=+1
x=-4(+1)+2
x=-4+2
x=-2
է) x=+3y+10
2(+3y+10)+4y-90
6y+10+4y-90
6y+20+4y-90
6y+4y=-20+90
10y=+70
y=+7
x=+3(7)+10
x=21+10
x=31
ը) x=-5y+7
3(-5y+7)-2y-5=0
-15y+21-2y-4=0
-15-y=-21+4
-17y=-17
y=1
x=-5(1)+1
x=-5+1
x=-4
թ)x=-2y-1
-6y-3-4y-7=0
-10y=+3+7
-10y=10
y=-1
x=-2(-1)-1
x=+2-1
x=1
ը)x=-4y-12
7(-4y-12)-2y-6=0
-28y-84-2y-6=0
-28y-2y+84+6
-30y=90
-y=-3
x=-4(-3-12)
x=+12-12
x=0