a) {2x+3y=4/.5
{3x+5y=7/.(-3)
{10x+15y=20
{-9x-15y= -21 x=-1
{x=-1
{10.(-1)+15y=20
{x=-1
{15y=30/:15
{x=-1
{y=2
b) {3x+5y=11/.4
{4x+7y=15/.(-3)
{12x+20y=44
{-12x-21y=-45 y=1
{y=1
{12x+20.1=44
{y=1
{12x=24/:12
{y=1
{x=2
c){-6x+2y=12/.3
{2x-3y=-11/.2
{-18x+6y-36
{4x-6y=-22 x=-1
{x=-1
{2.(-1)-3y=-11
{x=-1
{-3y=-9/:(-3)
{=-1
{=3
d) {3x-y=y+1
{x+y=2
{3x-2y=1
{x+y=2/.2
{3x+2y=1
{2x+2y=4 x=1
{3.1-2y=1
{x=1
{x=1
{-2y=-2/:(-2)
{x=1
{y=1
e) {1/2x+1/4y=1/2 /.(-4)
{4x+y=-4
{-2x-y=-2
{4x+y=-4+2x=-6 2x=-6/:2 x=-3
{x=-3
{4.(-3)+y=-4
{x=-3
{y=8
f)pierwsza klamerka zpodręcznika { }
potem - {2x-4+3y+3=18
{x-2y=-1
{2x+3y=19/.2
{x-2y=-1/.3
{4x+6y=38
{3x-6y=-3 7x=35/:7 x=5
{x=5
{4.5+6y=38
{x=5
{6y=18/:6
{x=5
{y=3