Question

Rezolvati prin metoda substitutiei urmatoarele sisteme de ecuatii. a.-x+y=4 5x+2y=8
b.
$- 3x + 4y = - 6 \\ 2x + y = 4$
$c.2x - 3y = - 3 \\ 3x + y = 12$
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Answer 1

Răspuns:

-x+y=4. < => y=4+x. <=>y=4+x.

5x+2y=8. 5x+2(4+x)=8. 5x+8+2x=8

<=> y=4+x. y=4+x. y=11

7x=0. <=> x=7. <=>