Răspuns:
Explicație pas cu pas:
{ 3 x + 2(y+1) = 7 => { 3 x + 2 y + 2 = 7 => { 3 x + 2 y = 7 - 2
{ 2(x-5) + 3y = - 10 => { 2 x - 10 + 3 y = - 10 => { 2 x + 3 y = - 10 + 10
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{ 3 x + 2 y = 5
{ 2 x + 3 y = 0
____________scad relatiile
x - y = 5 => x = y + 5
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Metoda substitutiei:
3 x + 2 y = 5
3 ( y + 5 ) + 2 y = 5
3 y + 15 + 2 y = 5
5 y = 5 - 15
y = - 10/5 => y = - 2
x = y + 5 = - 2 + 5 => x = 3
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Verific:
3 x + 2 y + 2 = 3 × 3 + 2 × ( - 2 ) + 2 = 9 - 4 + 2 = 7
2(x-5) + 3 y = 2 × ( 3-5) + 3 ×(-2) = - 4 - 6 = - 10
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Solutii: ( x; y) = ( 3; - 2)
