Question

Rozwiąż układy równań, strona 99 zad.5 matematyka z plusem :

a)

b)

c)

potrzebne pisać dokładnie co odjąć dodać itp

Answer 1

a)\left \{ {{x+3y=3} \atop {x-y=5 |+y}} \right

\left \{ {{x+3y=3} \atop {x=5-y}} \right

\left \{ {{5-y+3y=3} \atop {x=5-y}} \right

\left \{ {{5+2y=3 |-5} \atop {x=5-y}} \right

\left \{ {{2y= -2 |:2} \atop {x=5-y}} \right
\left \{ {{y=-1} \atop {x=5-y}} \right 

\left \{ {{y=-1} \atop {x=5-(-1)}} \right

\left \{ {{y=-1} \atop {x=6}} \right

b) \left \{ {{2x-y=10} \atop {x+5y=-17|-5y}} \right

\left \{ {{2x-y=10} \atop {x=-17-5y}} \right

\left \{ {{2(-17-5y)-y=10} \atop {x=-17-5y}} \right

\left \{ {{-34-10y-y=10} \atop {x=-17-5y}} \right

\left \{ {{-34-11y=10 |+34} \atop {x=-17-5y}} \right
\left \{ {{-11y=44 |: (-11)} \atop {x=-17-5y}} \right 

\left \{ {{y= -4} \atop {x=-17-5(-4)}} \right

\left \{ {{y=-4} \atop {x=-17+20}} \right

\left \{ {{y=-4} \atop {x=3}} \right

c)\left \{ {{3m+n=9 |-3m} \atop {2m-5n=-11}} \right

\left \{ {{n=9-3m} \atop {2m-5n=-11}} \right

\left \{ {{n=9-3m} \atop {2m-5(9-3m)=-11}} \right

\left \{ {{n=9-3m} \atop {2m-45+15m=-11 |+45}} \right

\left \{ {{n=9-3m} \atop {17m=34 |:17}} \right

\left \{ {{n=9-3m} \atop {m=2}} \right

\left \{ {{n=9-3*2} \atop {m=2}} \right

\left \{ {{n=9-6} \atop {m=2}} \right

\left \{ {{n=3} \atop {m=2}} \right
;)