Question

Rezolvati in multimea numerelor reale prin metoda substitutiei sistemul de ecuatii:
a 3x-y=-4 b x+y=6 c 2y-x=-3
x+2y=8 3x-5y=2 3y-2x=-7

Answer 1

a)3x-y=-4
3x−y+y=−4+y
3x=y−4
3x/3=y−4/3
b)x+y=6
x+y+−y=6+−y
x=−y+6
c)2y-x=-3 
−x+2y+−2y=−3+−2y
−x=−2y−3
−x/−1=−2y−3/−1
x=2y+3
d)x+2y=8 
x+2y+−2y=8+−2y
x=−2y+8
e)3x-5y=2
3x−5y+5y=2+5y
3x=5y+2
3x/3=5y+2/3
x=5/3y+2/3
f)3y-2x=-7
−2x+3y+−3y=−7+−3y
−2x=−3y−7
−2x/−2=−3y−7/−2
x=3/2y+7/2