Question

exercițiul 6, va rog!

Answer 1

Răspuns:

a)-×+y=7

×=5-3y

-(5-3y)+y=7

y=3

×=5-3×3

×=-4

(-×,y)=(-4,3)

-(-4)+3=7

-4+3×3=5

7=7

5=5

b)×+y=4

×=14+y

14+y+y=4

y=-5

x=14-5

x=9

c)3×+y=13

y=7-×

3×+7-×=13

×=3

y=7-3=4

d)3y=7-5×

-×-3y=1

-×-(7-5×)=1

-2-3y=1

×=2

y=-1