Răspuns:
a) y=5; x=2
b)y=2; x=-1/5
Explicație pas cu pas:
a) -2x+y=1=>y=1+2x
7x-2y=4=>7x-2(1+2x)=4=>7x-2-4x=4=>3x=6=>x=2
y=1+2x=>y=1+4=>y-5
b)5x-2y=-5=>5x=2y-5=>x=(2y-5)/5
-10x+3y=8=>-10(2y-5)/5+3y=8=>-2(2y-5)+3y=8=>-4y+10+3y=8=>-y=-2=>y=2
x=(4-5)/5=>x=-1/5
