Question

Dau coroană, vreau să primesc răspunsuri serioase!


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Answer 1

Răspuns:

x=1; y=2 ∈ pentru primele 2 sisteme de ecuatii

x=-$\frac{27}{13}$ ; y=$\frac{24}{13}$ ∈ pentru ultimul sistem de ecuatie

Explicație pas cu pas:

$\left \{x+5y-11=0} \atop{3x-6y+9=0\atop {{4x+7y-10=0}}} \right. =>\left \{ {{x=-5y+11} \atop{3(-5y+11)-6y+9\atop {{4(-5y+11)+7y-10}}} \right.=>\\=>\left \{ {{x=-5y+11} \atop{-15y+33-6y+9=0\atop {{-20y+44+7y-10=0}}} \right.=>\left \{ {{x=-5y+11} \atop{-21+42=0\atop {{-13y+34=0}}} \right.=>\\=>\left \{ {{x=-5y+11} \atop{-21y+42\atop {{-13y+34}}} \right.=>\left \{ {{x=-5+11} \atop{y=\frac{42}{21} \atop {{y=\frac{34}{13} }}} \right.=>\\=>\left \{ {{x=-5y+11} \atop{y=2\atop {{y=\frac{34}{13} }}} \right=>$

$\left \{ {{x=-5*2+11} \atop {x=-5(\frac{34}{13})+11 }} \right. =>\left \{ {{x=1} \atop {x=\frac{-170}{13}+11 }} \right.=>\\\left \{ {{x=1} \atop {x=-5(\frac{-170+143}{13} }} \right. =>\left \{ {{x=1} \atop {x=-\frac{27}{13} }} \right.$

$\left \{ {{1+5*2-11=0} \atop{3*1-6*2+9=0\atop {{4*(-\frac{27}{13}) +7*\frac{34}{13} -10=0}}} \right.=>\\=>\left \{ {{11-11=0} \atop{0-9+9=0\atop {{-\frac{108}{13}+\frac{238}{13}-10 =0}}} \right.=>aducem-ultimul-sistem-\\,la -un -numitor-comun\\=>\left \{ {{0=0} \atop{0=0\atop {{\frac{-108+238-130}{13} =0}}} \right.=>\left \{ {{0=0} \atop{0=0\atop {{\frac{130-130}{13} =0}}} \right.=>\\=>\left \{ {{0=0} \atop{0=0\atop {{0 =0}}} \right. A$