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a fost răspuns

Sa se determine multimile x,y care apartin lui R pentru care au loc egalitatiile :
a) (2x-5,4-y)= (5,8)
b) (4x-3,4y+3)=(9,-9)
C) (x^2+x,9)=(6,y^2 +8y)
D) (x^2+y,6y)=(11,12)
E)(2x+3;5)=(y;13-3y)
F)(2x-3y,y-2) = (y,x)
Va rog ajutati-ma

Răspuns :

Mikkka
a) 2x-5=5⇒ 2x=5+5⇒2x=10⇒x=10:2⇒x=5
4-y=8⇒y=4-8⇒y=-4

b) 4x-3=9⇒4x=9+3⇒4x=12⇒x=12:4⇒x=3
4y+3=-9⇒4y=-9-3⇒4y=-12⇒y=-12:4⇒y=-3

c) x²+x=6⇒ x²+x-6=0⇒(x+3)(x-2)=0⇒x=-3 sau x=2
y²+8y=9⇒ y²+8y-9=0⇒ (y+9)(y-1)=0 ⇒ y=-9 sau y=1

d)6y=12⇒y=12:6⇒y=2
x²+2=11⇒x²=11-2⇒x²=9⇒ x=3 sau x=-3

e)13-3y=5⇒3y=13-5⇒3y=8⇒y=8/3
2x+3=8/3⇒2x=8/3-9/3⇒2x=-1/3⇒x=-1/6

f)2x-3y=y⇒2x=4y⇒x=2y
y-2=2y⇒-2=2y-y⇒-2=y⇒y=-2
x=-4